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1.
Nat Commun ; 12(1): 4132, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226556

RESUMO

Precise control of gene expression is critical for biological research and biotechnology. However, transient plasmid transfections in mammalian cells produce a wide distribution of copy numbers per cell, and consequently, high expression heterogeneity. Here, we report plasmid-based synthetic circuits - Equalizers - that buffer copy-number variation at the single-cell level. Equalizers couple a transcriptional negative feedback loop with post-transcriptional incoherent feedforward control. Computational modeling suggests that the combination of these two topologies enables Equalizers to operate over a wide range of plasmid copy numbers. We demonstrate experimentally that Equalizers outperform other gene dosage compensation topologies and produce as low cell-to-cell variation as chromosomally integrated genes. We also show that episome-encoded Equalizers enable the rapid generation of extrachromosomal cell lines with stable and uniform expression. Overall, Equalizers are simple and versatile devices for homogeneous gene expression and can facilitate the engineering of synthetic circuits that function reliably in every cell.


Assuntos
Variações do Número de Cópias de DNA , Dosagem de Genes , Regulação da Expressão Gênica , Animais , Linhagem Celular , Expressão Gênica , MicroRNAs , Plasmídeos , Transfecção
2.
Chimia (Aarau) ; 75(6): 535-538, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34233820

RESUMO

Aiming at studying cooperativity effects between amino acids in easily accessible protein models, we have explored the chemistry of peptide dendrimers, which we obtain as pure products by solid-phase peptide synthesis using a branching diamino acid such as lysine at every second or third position in a peptide sequence, followed by reverse-phase HPLC purification. This article reviews discoveries driven by combinatorial library synthesis and screening, including enantioselective esterase and aldolase enzyme models, cobalamin binding and peroxidase dendrimers, glycopeptide dendrimer biofilm inhibitors and their X-ray crystal structures as complexes with lectins, antimicrobial peptide dendrimers active against multidrug resistant Gram-negative bacteria, and transfection reagents for siRNA and CRISPR-Cas9 plasmid DNA. Latest developments include cheminformatics and artificial intelligence for exploring the peptide chemical space, and the principle of stereorandomization to understand the role of peptide chirality in activity.


Assuntos
Anti-Infecciosos , Dendrímeros , Inteligência Artificial , Indicadores e Reagentes , Peptídeos , Transfecção
3.
Int J Nanomedicine ; 16: 4391-4407, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234433

RESUMO

Background: Gold nanocages have been widely used as multifunctional platforms for drug and gene delivery, as well as photothermal agents for cancer therapy. However, their potential as gene delivery systems for cancer treatment has been reported in combination with chemotherapeutics and photothermal therapy, but not in isolation so far. The purpose of this work was to investigate whether the conjugation of gold nanocages with the cancer targeting ligand lactoferrin, polyethylene glycol and polyethylenimine could lead to enhanced transfection efficiency on prostate cancer cells in vitro, without assistance of external stimulation. Methods: Novel lactoferrin-bearing gold nanocages conjugated to polyethylenimine and polyethylene glycol have been synthesized and characterized. Their transfection efficacy and cytotoxicity were assessed on PC-3 prostate cancer cell line following complexation with a plasmid DNA. Results: Lactoferrin-bearing gold nanocages, alone or conjugated with polyethylenimine and polyethylene glycol, were able to condense DNA at conjugate:DNA weight ratios 5:1 and higher. Among all gold conjugates, the highest gene expression was obtained following treatment with gold complex conjugated with polyethylenimine and lactoferrin, at weight ratio 40:1, which was 1.71-fold higher than with polyethylenimine. This might be due to the increased DNA cellular uptake observed with this conjugate, by up to 8.65-fold in comparison with naked DNA. Conclusion: Lactoferrin-bearing gold nanocages conjugates are highly promising gene delivery systems to prostate cancer cells.


Assuntos
Portadores de Fármacos/química , Técnicas de Transferência de Genes , Ouro/química , Lactoferrina/química , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , DNA/administração & dosagem , DNA/química , DNA/genética , Terapia Genética , Humanos , Masculino , Plasmídeos/genética , Polietilenoglicóis/química , Polietilenoimina/química , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/terapia , Transfecção
4.
Nano Lett ; 21(13): 5697-5705, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34228937

RESUMO

Polyelectrolyte complex particles assembled from plasmid DNA (pDNA) and poly(ethylenimine) (PEI) have been widely used to produce lentiviral vectors (LVVs) for gene therapy. The current batch-mode preparation for pDNA/PEI particles presents limited reproducibility in large-scale LVV manufacturing processes, leading to challenges in tightly controlling particle stability, transfection outcomes, and LVV production yield. Here we identified the size of pDNA/PEI particles as a key determinant for a high transfection efficiency with an optimal size of 400-500 nm, due to a cellular-uptake-related mechanism. We developed a kinetics-based approach to assemble size-controlled and shelf-stable particles using preassembled nanoparticles as building blocks and demonstrated production scalability on a scale of at least 100 mL. The preservation of colloidal stability and transfection efficiency was benchmarked against particles generated using an industry standard protocol. This particle manufacturing method effectively streamlines the viral manufacturing process and improves the production quality and consistency.


Assuntos
DNA , Polietilenoimina , DNA/genética , Tamanho da Partícula , Plasmídeos/genética , Reprodutibilidade dos Testes , Transfecção
5.
J Cardiothorac Surg ; 16(1): 194, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34233689

RESUMO

OBJECTIVE: C-erbB-2 has been confirmed to be an oncogene that participates in cell growth, differentiation and division of tumors. We are wondered if its silenced expression can exert an anti-tumor effect. Therefore, this study is conducted to investigate the mechanism of C-erbB-2 silencing and IGF-1 pathway on esophageal carcinoma (EC) cell biological behaviors. METHODS: The objects of study were 84 EC patients from Heping Hospital Affiliated to Changzhi Medical College, with the collection of EC tissue and adjacent normal tissue (> 5 cm away from cancer tissue). C-erbB-2 protein expression in EC tissues was detected by immunohistochemistry. Human EC cell line Eca-109 was purchased from Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. Based on different transfection protocols, EC cells with logarithmic growth phase of 3-5 passages were divided into blank control group, oe-C-erbB-2 NC group, siRNA C-erbB-2 NC group, oe-C-erbB-2 group, siRNA C-erbB-2 group, OSI-906 group, Rg5 group, Rg5 + siRNA C-erbB-2 NC group and Rg5 + siRNA C-erbB-2 group. Cell proliferation was detected by MTT assay; cell cycle distribution and apoptosis by flow cytometry; C-erbB-2, IGF-1, IGF-1R and Akt mRNA and protein expressions by qRT-PCR and western blot; and cell invasion and migration by Transwell assay and scratch test. Tumor growth was observed in male BALB/c nude mice (Shanghai Experimental Animal Center) based on Eca109 cell implantation, raising, and measurement. RESULTS: C-erbB-2, IGF-1, IGF-1R and Akt expression were higher in EC tissues than those in adjacent tissues (all P < 0.05). Compared with blank control group, both si-C-erbB-2 and OSI-906 groups had decreased IGF-1, IGF-1R and Akt mRNA and protein expressions, decreased cell proliferation, migration and invasion, prolonged G0/G1 phase, shortened S phase, increased cell apoptosis, and inhibited tumor growth (all P < 0.05); while opposite trends were detected in C-erbB-2 vector and Rg5 groups (all P < 0.05), without statistical differences in siRNA C-erbB-2 + Rg5 group (all P > 0.05). CONCLUSION: Silencing C-erbB-2 expression may inhibit EC cell proliferation, promote cell apoptosis and block cell cycle progression by inhibiting IGF-1 pathway activation. The beneficial effect of silencing C-erbB-2 expression can be reversed by promoting the activation of IGF-1 pathway. Findings in our study may provide potential reference for understanding the molecular mechanism of EC and supply possible axis for preventing the development of EC from the perspective of molecular biology.


Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Inativação Gênica/fisiologia , Fator de Crescimento Insulin-Like I/metabolismo , Receptor ErbB-2/genética , Adulto , Idoso , Animais , Apoptose/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Feminino , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Transplante de Neoplasias , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptor IGF Tipo 1 , Transfecção
6.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 35(7): 855-861, 2021 Jul 15.
Artigo em Chinês | MEDLINE | ID: mdl-34308593

RESUMO

Objective: To investigate the role of p22phox and NOX5 in autophagy and apoptosis of osteoblasts induced by hypoxia. Methods: The skull tissue of newborn rats was cut into small pieces, and the osteoblasts were separated and purified by the tissue block adherent method and the differential adherent method. The first generation cells were harvested and identified by HE staining, Alizarin red staining, alkaline phosphatase (ALP) staining, and flow cytometry. A three-gas incubator was used to prepare a hypoxia model of osteoblasts. At 0, 3, 6, 12, and 24 hours of hypoxia, the expressions of p22phox, NOX5, and LC3Ⅱ/Ⅰ were detected by Western blot, and the level of reactive oxygen species (ROS) and cell apoptosis rate were detected by flow cytometry. And the time point of the highest level of ROS was selected as the hypoxia time point for subsequent experiments. The first generation osteoblasts were divided into normal group, si-p22phox hypoxia group, and si-NOX5 hypoxia group and subjected to corresponding transfection and hypoxia treatment. The inhibition efficiency of si-p22phox and si-NOX5 were detected by RT-PCR. Then the osteoblasts were divided into normal group, si-NC hypoxia group, si-p22phox hypoxia group, and si-NOX5 hypoxia group. After transfection and hypoxia treatment, Western blot was used to detect the expressions of p22phox, NOX5, autophagy-related proteins (LC3Ⅱ/Ⅰ, Beclin), and apoptosis-related proteins (Bcl-2, Bax), and flow cytometry was used to detect the cell apoptosis rate and level of ROS. The first generation osteoblasts were divided into a hypoxia group for 12 hours (hypoxia group) and a group that simultaneously inhibited si-p22phox and si-NOX5 and hypoxia for 12 hours (inhibition+hypoxia group). The expressions of Beclin and Bax were observed by immunofluorescence staining after the corresponding treatment. Results: After identification, the isolated cells were osteoblasts. After hypoxia treatment, the relative expressions of p22phox, NOX5, and LC3Ⅱ/Ⅰ proteins and the apoptosis rate of osteoblasts gradually increased ( P<0.05), and the level of ROS also significantly increased ( P<0.05) and reached the peak value at 12 hours. The 12-hour hypoxia model was selected for subsequent experiments. Silencing the p22phox gene did not affect the expression of NOX5, and silencing the NOX5 gene did not affect the expression of p22phox. Compared with hypoxia treatment, the relative expressions of LC3Ⅱ/Ⅰ, Beclin, and Bax proteins after inhibiting the expression of p22phox or NOX5 gene significantly decreased ( P<0.05), the relative expression of Bcl-2 protein significantly increased ( P<0.05), the cell apoptosis rate and level of ROS also significantly decreased ( P<0.05). After silencing the expressions of p22phox and NOX5 genes at the same time, the immunofluorescence staining showed that the fluorescence of Beclin and Bax were weak. Conclusion: Inhibiting the expressions of p22phox and NOX5 genes can reduce the level of ROS in osteoblasts under hypoxia-induced conditions, and at the same time reduce autophagy and apoptosis, especially attenuate the excessive apoptosis of cells in the early to late stages, and strengthen the hypoxic osteoblasts proliferation.


Assuntos
Apoptose , Autofagia , Animais , Hipóxia , Osteoblastos , Ratos , Transfecção
7.
Mater Sci Eng C Mater Biol Appl ; 127: 112184, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225845

RESUMO

Polyethyleneimine (PEI) polymers are known to compact DNA strands into spheroid, toroid, or rod structures. A formulation with mannose-grafted PEI (PEIm), however, was reported to compact DNA into ~100 nm spheroids that indented like thin-walled pressurized shells. The goal of the study is to understand why mannose bristles divert the traditional pathway of PEI-DNA compaction to produce shell-like structures, and to manipulate the process so that proteins can be packed into the core of the assembling shells for co-delivering DNA and proteins into cells. DLS, AFM, and TEM imaging provide a consistent picture that BSA proteins can be packed into the shells without altering the shell architecture, as long as the proteins were added during the time course of shell assembly. Force spectroscopy studies reveal that DNA shells that buckle also have a rich surface-coating of mannose, indicating that a micelle-like partitioning of hydrophobic and hydrophilic layers governs shell assembly. When HEK293T cells are spiked with BSA-laden DNA shells, co-transfection of DNA and BSA is observed at higher levels than control formulations. Distinct micron-sized features appear having both green fluorescence from BSA-FITC and blue fluorescence from NucBlue DNA stain, suggesting BSA release in nucleus and secretory granules. With DNA nanocontainers, proteins can take advantage of the efficiency of PEI-based DNA transfection for hitchhiking into cells while being shielded from the challenges of the intracellular route. DNA nanocontainers are rapid to assemble, not dependent on the DNA sequence, and can be adapted for different protein types; thereby having potential to serve as a high-throughput platform in scenarios where DNA and protein have to be released at the same site and time within cells (e.g., theranostics, multiplexed co-delivery, gene editing).


Assuntos
DNA , Polietilenoimina , Células HEK293 , Humanos , Micelas , Polímeros , Transfecção
8.
Mater Sci Eng C Mater Biol Appl ; 127: 112243, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225883

RESUMO

An effective delivery vehicle of genetic materials to their target site is the key to a successful gene therapy. In many cases, nanoparticles are used as the vehicle of choice and the efficiency of the delivery relies heavily on the physicochemical properties of the nanoparticles. Microfluidics, although being a low throughput method, has been increasingly researched for the preparation of nanoparticles. A range of superior properties were claimed in the literature for microfluidic-prepared platforms, but no evidence on direct comparison of the properties of the nanoparticles prepared by microfluidics and conventional high throughput method exists, leaving the industry with little guidance on how to select effective large-scale nanoparticle manufacturing method. This study used plasmid DNA-loaded PLGA-Eudragit nanoparticles as the model system to critically compare the nanoparticles prepared by conventional and microfluidics-assisted nanoprecipitation. The PLGA-Eudragit nanoparticles prepared by microfluidics were found to be statistically significantly larger than the ones prepared by conventional nanoprecipitation. PLGA-Eudragit nanoparticle prepared conventionally showed higher DNA loading efficiency. Although the DNA-loaded nanoparticles prepared by both methods did not induce significant cytotoxicity, the transfection efficiency was found to be higher for the ones prepared conventionally which has good potential for plasmid delivery. This study for the first time provides a direct comparison of the DNA-loaded nanoparticles prepared by microfluidic and conventional methods. The findings bring new insights into critical evaluation of the selection of manufacturing methods of nanoparticles for future gene therapy.


Assuntos
Microfluídica , Nanopartículas , DNA , Tamanho da Partícula , Polímeros , Transfecção
9.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34210100

RESUMO

Cas endonuclease-mediated genome editing provides a long-awaited molecular biological approach to the modification of predefined genomic target sequences in living organisms. Although cas9/guide (g)RNA constructs are straightforward to assemble and can be customized to target virtually any site in the plant genome, the implementation of this technology can be cumbersome, especially in species like triticale that are difficult to transform, for which only limited genome information is available and/or which carry comparatively large genomes. To cope with these challenges, we have pre-validated cas9/gRNA constructs (1) by frameshift restitution of a reporter gene co-introduced by ballistic DNA transfer to barley epidermis cells, and (2) via transfection in triticale protoplasts followed by either a T7E1-based cleavage assay or by deep-sequencing of target-specific PCR amplicons. For exemplification, we addressed the triticale ABA 8'-hydroxylase 1 gene, one of the putative determinants of pre-harvest sprouting of grains. We further show that in-del induction frequency in triticalecan beincreased by TREX2 nuclease activity, which holds true for both well- and poorly performing gRNAs. The presented results constitute a sound basis for the targeted induction of heritable modifications in triticale genes.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Edição de Genes/métodos , Proteínas de Plantas/metabolismo , Triticale/metabolismo , Sistemas CRISPR-Cas , Sistema Enzimático do Citocromo P-450/genética , Genes Reporter , Mutação INDEL , Mutagênese Sítio-Dirigida , Proteínas de Plantas/genética , Transfecção , Triticale/genética
10.
Mater Sci Eng C Mater Biol Appl ; 126: 112161, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34082966

RESUMO

Nowadays, the nanoparticle-based delivery approach is becoming more and more attractive in gene therapy due to its low toxicity and immunogenicity, sufficient packaging capacity, targeting, and straightforward, low-cost, large-scale good manufacturing practice (GMP) production. A number of research works focusing on multilayer structures have explored different factors and parameters that can affect the delivery efficiency of pDNA. However, there are no systematic studies on the performance of these structures for enhanced gene delivery regarding the gene loading methods, the use of additional organic components and cell/particle incubation conditions. Here, we conducted a detailed analysis of different parameters such as (i) strategy for loading pDNA into carriers, (ii) incorporating both pDNA and organic additives within one carrier and (iii) variation of cell/particle incubation conditions, to evaluate their influence on the efficiency of pDNA delivery with multilayer structures consisting of inorganic cores and polymer layers. Our results reveal that an appropriate combination of all these parameters leads to the development of optimized protocols for high transfection efficiency, compared to the non-optimized process (> 70% vs. < 7%), and shows a good safety profile. In conclusion, we provide the proof-of-principle that these multilayer structures with the developed parameters are a promising non-viral platform for an efficient delivery of nucleic acids.


Assuntos
DNA , Técnicas de Transferência de Genes , Terapia Genética , Tamanho da Partícula , Plasmídeos/genética , Transfecção
11.
Mater Sci Eng C Mater Biol Appl ; 126: 112189, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34082988

RESUMO

The incorporation of specific therapeutic gene into glioblastoma offers potent therapeutic strategy to treat the disease. Non-viral gene delivery vectors are of particular interest due to their tuneable transfection efficiency and easy scale-up. Herein, we demonstrate successful delivery of plasmid encoding tumor necrosis factor (TNF)-related apoptosis-inducing ligand (pTRAIL) using arginine-conjugated tocopherol lipid (AT) nanovesicles into glioblastoma cell lines. Another cationic lipid, glycine-conjugated tocopherol lipid (GT) having glycine in the head group region is also synthesized as a control lipid. Both lipid-derived liposomes effectively condensed the pDNA and the corresponding biomacromolecular assemblies (lipoplexes) are efficiently transfected into different cell lines. AT-based liposomes exhibit higher transfection efficacy in various cell lines, particularly selective in glioma cell lines. At an optimized N/P ratio, both the liposomal formulations show low cytotoxicity. AT-based lipoplexes have superior cellular uptake in U87 than the control lipid GT. The expression of TRAIL protein regulated death receptor and apoptosis signaling pathway is assayed by western blot using transfection of AT-based/pTRAIL into U87 cell lines. Induction of apoptosis in U87 cells exposed to AT-based/pTRAIL plasmid is evaluated by MTT assay as well as Annexin V-propidium iodide dual-staining assay. All results indicate that the developed AT-based/pTRAIL system offers a potentially safe and efficient therapeutic strategy for glioblastoma gene therapy.


Assuntos
Glioblastoma , Apoptose , Arginina , Linhagem Celular Tumoral , Glioblastoma/tratamento farmacológico , Humanos , Lipídeos , Lipossomos , Plasmídeos/genética , Tocoferóis , Transfecção
12.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 37(6): 501-506, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34060444

RESUMO

Objective To investigate the effect of silencing calreticulin (CALR) gene on the apoptosis and intracellular Ca2+ concentration in HSC-LX2 human hepatic stellate cells. Methods Small interfering RNA (siRNA) targeting CALR was designed and transfected into HSC-LX2 cells by lipofectamine transfection, and then the cells with CALR knockdown were screened out. Apoptosis was detected by flow cytometry combined with annexin V-FITC/PI labeling. The intracellular Ca2+ concentration which was loaded with Fluo3-AM (calcium ion fluorescent probe) was observed by laser confocal microscope. The mRNA and protein levels of CALR, Bcl2 and BAX were detected by reverse-transcription PCR and Western blotting. Results Knockdown of CALR led to the increase of intracellular Ca2+ concentration, the increased apoptosis of HSC-LX2 cells, the up-regulation of BAX expression, down-regulation of Bcl2 and the obvious raise of BAX/Bcl2 ratio. Conclusion Knockdown of CALR can increase intracellular Ca2+ concentration, up-regulate the ratio of BAX/Bcl2 and promote the apoptosis of HSC-LX2 cells.


Assuntos
Calreticulina , Células Estreladas do Fígado , Apoptose , Calreticulina/genética , Humanos , RNA Interferente Pequeno/genética , Transfecção
13.
Colloids Surf B Biointerfaces ; 205: 111881, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34062346

RESUMO

Nuclear breakdown was found to be the dominant route for DNA entry into the nucleus in actively dividing cells. The possibility that alternative routes contribute to DNA entry into the nucleus, however, cannot be ruled out. Here we address the process of lipofection by monitoring the localization of fluorescently-labelled DNA plasmids at the single-cell level by confocal imaging in living interphase cells. As test formulation we choose the cationic 3ß-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic helper lipid dioleoylphosphatidylethanolamine (DOPE) with plasmidic DNA pre-condensed by means of protamine. By exploiting the spectral shift of the fluorescent dye FM4-64 (N-(3-triethylammoniumpropyl)-4-(p-diethylaminophenylhexatrienyl)-pyridinium 2Br) we monitor the position of the nuclear envelope (NE), while concomitantly imaging the whole nucleus (by Hoechst) and the DNA (by Cy3 fluorophore) in a multi-channel 3D confocal imaging experiment. Reported results show that DNA clusters are typically associated with the NE membrane in the form of tubular invaginations spanning the nuclear environment, but not completely trapped within the NE invaginations, i.e. the DNA may use these NE regions as entry-points towards the nucleus. These observations pave the way to investigating the molecular details of the postulated processes for a better exploitation of gene-delivery vectors, particularly for applications in non-dividing cells.


Assuntos
Lipossomos , Membrana Nuclear , DNA , Microscopia Confocal , Transfecção
14.
Viruses ; 13(6)2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34064066

RESUMO

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2), the causative agent of coronavirus disease 19 (COVID-19), enters cells through attachment to the human angiotensin converting enzyme 2 (hACE2) via the receptor-binding domain (RBD) in the surface/spike (S) protein. Several pseudotyped viruses expressing SARS-CoV-2 S proteins are available, but many of these can only infect hACE2-overexpressing cell lines. Here, we report the use of a simple, two-plasmid, pseudotyped virus system comprising a SARS-CoV-2 spike-expressing plasmid and an HIV vector with or without vpr to investigate the SARS-CoV-2 entry event in various cell lines. When an HIV vector without vpr was used, pseudotyped SARS-CoV-2 viruses produced in the presence of fetal bovine serum (FBS) were able to infect only engineered hACE2-overexpressing cell lines, whereas viruses produced under serum-free conditions were able to infect a broader range of cells, including cells without hACE2 overexpression. When an HIV vector containing vpr was used, pseudotyped viruses were able to infect a broad spectrum of cell types regardless of whether viruses were produced in the presence or absence of FBS. Infection sensitivities of various cell types did not correlate with mRNA abundance of hACE2, TMPRSS2, or TMPRSS4. Pseudotyped SARS-CoV-2 viruses and replication-competent SARS-CoV-2 virus were equally sensitive to neutralization by an anti-spike RBD antibody in cells with high abundance of hACE2. However, the anti-spike RBD antibody did not block pseudotyped viral entry into cell lines with low abundance of hACE2. We further found that CD147 was involved in viral entry in A549 cells with low abundance of hACE2. Thus, our assay is useful for drug and antibody screening as well as for investigating cellular receptors, including hACE2, CD147, and tyrosine-protein kinase receptor UFO (AXL), for the SARS-CoV-2 entry event in various cell lines.


Assuntos
HIV/genética , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/fisiologia , Internalização do Vírus , Células CACO-2 , Linhagem Celular , Vetores Genéticos , Células HEK293 , Humanos , Plasmídeos , SARS-CoV-2/genética , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/genética , Transfecção , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo
15.
Nucleic Acids Res ; 49(11): 6100-6113, 2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34107015

RESUMO

Pulmonary diseases offer many targets for oligonucleotide therapeutics. However, effective delivery of oligonucleotides to the lung is challenging. For example, splicing mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) affect a significant cohort of Cystic Fibrosis (CF) patients. These individuals could potentially benefit from treatment with splice switching oligonucleotides (SSOs) that can modulate splicing of CFTR and restore its activity. However, previous studies in cell culture used oligonucleotide transfection methods that cannot be safely translated in vivo. In this report, we demonstrate effective correction of a splicing mutation in the lung of a mouse model using SSOs. Moreover, we also demonstrate effective correction of a CFTR splicing mutation in a pre-clinical CF patient-derived cell model. We utilized a highly effective delivery strategy for oligonucleotides by combining peptide-morpholino (PPMO) SSOs with small molecules termed OECs. PPMOs distribute broadly into the lung and other tissues while OECs potentiate the effects of oligonucleotides by releasing them from endosomal entrapment. The combined PPMO plus OEC approach proved to be effective both in CF patient cells and in vivo in the mouse lung and thus may offer a path to the development of novel therapeutics for splicing mutations in CF and other lung diseases.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/terapia , Pulmão/metabolismo , Morfolinos/administração & dosagem , Splicing de RNA , Animais , Células Cultivadas , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Humanos , Camundongos , Mutação , Peptídeos , Mucosa Respiratória/metabolismo , Transfecção
16.
Methods Mol Biol ; 2277: 49-67, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080144

RESUMO

Defects in human mitochondrial genome can cause a wide range of clinical disorders that still do not have efficient therapies. The natural pathway of small noncoding RNA import can be exploited to address therapeutic RNAs into the mitochondria. To create an approach of carrier-free targeting of RNA into living human cells, we designed conjugates containing a cholesterol residue and developed the protocols of chemical synthesis of oligoribonucleotides conjugated with cholesterol residue through cleavable pH-triggered hydrazone bond. The biodegradable conjugates of importable RNA with cholesterol can be internalized by cells in a carrier-free manner; RNA can then be released in the late endosomes due to a change in pH and partially targeted into mitochondria. Here we provide detailed protocols for solid-phase and "in solution" chemical synthesis of oligoribonucleotides conjugated to a cholesterol residue through a hydrazone bond. We describe the optimization of the carrier-free cell transfection with these conjugated RNA molecules and methods for evaluating the cellular and mitochondrial uptake of lipophilic conjugates.


Assuntos
Mitocôndrias/genética , Oligorribonucleotídeos/síntese química , RNA/química , Transfecção/métodos , Células Cultivadas , Colesterol/química , Humanos , Hidrazonas/química , Concentração de Íons de Hidrogênio , RNA/administração & dosagem
17.
Molecules ; 26(10)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34065854

RESUMO

Gaining insight into the pharmacology of ligand engagement with G-protein coupled receptors (GPCRs) under biologically relevant conditions is vital to both drug discovery and basic research. NanoLuc-based bioluminescence resonance energy transfer (NanoBRET) monitoring competitive binding between fluorescent tracers and unmodified test compounds has emerged as a robust and sensitive method to quantify ligand engagement with specific GPCRs genetically fused to NanoLuc luciferase or the luminogenic HiBiT peptide. However, development of fluorescent tracers is often challenging and remains the principal bottleneck for this approach. One way to alleviate the burden of developing a specific tracer for each receptor is using promiscuous tracers, which is made possible by the intrinsic specificity of BRET. Here, we devised an integrated tracer discovery workflow that couples machine learning-guided in silico screening for scaffolds displaying promiscuous binding to GPCRs with a blend of synthetic strategies to rapidly generate multiple tracer candidates. Subsequently, these candidates were evaluated for binding in a NanoBRET ligand-engagement screen across a library of HiBiT-tagged GPCRs. Employing this workflow, we generated several promiscuous fluorescent tracers that can effectively engage multiple GPCRs, demonstrating the efficiency of this approach. We believe that this workflow has the potential to accelerate discovery of NanoBRET fluorescent tracers for GPCRs and other target classes.


Assuntos
Ligação Competitiva , Técnicas de Transferência de Energia por Ressonância de Bioluminescência/métodos , Luciferases/metabolismo , Substâncias Luminescentes/metabolismo , Aprendizado de Máquina , Receptores Acoplados a Proteínas G/metabolismo , Descoberta de Drogas/métodos , Células HEK293 , Humanos , Ligantes , Simulação de Acoplamento Molecular , Ligação Proteica , Receptores Acoplados a Proteínas G/genética , Transfecção
18.
Molecules ; 26(10)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34065886

RESUMO

Nujiangexanthone A (NJXA), a bioactive component isolated from the leaves of Garcinia nujiangensis, has been reported to exhibit anti-inflammatory, antioxidant, and antitumor effects. Our previous work has shown that NJXA induced G0/1 arrest and apoptosis, thus suppressing cervical cancer cell growth. The present study provides new evidence that NJXA can induce cell death in HeLa cells by promoting mitophagy. We first identified that NJXA triggered GFP-LC3 and YFP-Parkin puncta accumulation, which are biomarkers of mitophagy. Moreover, NJXA degraded the mitochondrial membrane proteins Tom20 and Tim23 and mitochondrial fusion proteins MFN1 and MFN2, downregulated Parkin, and stabilized PINK1. Additionally, we revealed that NJXA induced lysosome degradation and colocalization of mitochondria and autophagosomes, which was attenuated by knocking down ATG7, the key regulator of mitophagy. Furthermore, since mitophagy is induced under starvation conditions, we detected the cytotoxic effect of NJXA in nutrient-deprived HeLa cells and observed better cytotoxicity. Taken together, our work contributes to the further clarification of the mechanism by which NJXA inhibits cervical cancer cell proliferation and provides evidence that NJXA has the potential to develop anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Garcinia/química , Mitofagia/efeitos dos fármacos , Extratos Vegetais/farmacologia , Neoplasias do Colo do Útero/metabolismo , Xantonas/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Autofagossomos/metabolismo , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/metabolismo , Proliferação de Células/genética , Feminino , Técnicas de Inativação de Genes , Células HeLa , Humanos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Mitofagia/genética , Nutrientes/deficiência , Folhas de Planta/química , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transfecção , Ubiquitina-Proteína Ligases/metabolismo , Neoplasias do Colo do Útero/patologia
19.
PLoS Pathog ; 17(6): e1009683, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34166473

RESUMO

COVID-19 is a global crisis of unimagined dimensions. Currently, Remedesivir is only fully licensed FDA therapeutic. A major target of the vaccine effort is the SARS-CoV-2 spike-hACE2 interaction, and assessment of efficacy relies on time consuming neutralization assay. Here, we developed a cell fusion assay based upon spike-hACE2 interaction. The system was tested by transient co-transfection of 293T cells, which demonstrated good correlation with standard spike pseudotyping for inhibition by sera and biologics. Then established stable cell lines were very well behaved and gave even better correlation with pseudotyping results, after a short, overnight co-incubation. Results with the stable cell fusion assay also correlated well with those of a live virus assay. In summary we have established a rapid, reliable, and reproducible cell fusion assay that will serve to complement the other neutralization assays currently in use, is easy to implement in most laboratories, and may serve as the basis for high throughput screens to identify inhibitors of SARS-CoV-2 virus-cell binding and entry.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , Bioensaio/métodos , COVID-19/virologia , Receptores de Coronavírus/metabolismo , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Enzima de Conversão de Angiotensina 2/genética , COVID-19/sangue , Fusão Celular , Células HEK293 , Humanos , Receptores de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/genética , Transfecção , Ligação Viral
20.
Nat Protoc ; 16(7): 3596-3624, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34172975

RESUMO

Deaminase fused-Cas9 base editing technologies have enabled precise single-nucleotide genomic editing without the need for the introduction of damaging double-stranded breaks and inefficient homology-directed repair. However, current methods to isolate base-edited cell populations are ineffective, especially when utilized with human pluripotent stem cells, a cell type resistant to genome modification. Here, we outline a series of methods that employ transient reporters of editing enrichment (TREE) to facilitate the highly efficient single-base editing of human cells at precise genomic loci. Briefly, these transient reporters of editing enrichment based methods employ a transient episomal fluorescent reporter that allows for the real-time, flow-cytometry-based enrichment of cells that have had single nucleotide changes at precise genomic locations. This protocol details how these approaches can enable the rapid (~3-4 weeks) and efficient (clonal editing efficiencies >80%) generation of biallelic or multiplexed edited isogenic hPSC lines using adenosine and cytosine base editors.


Assuntos
Adenosina/metabolismo , Citosina/metabolismo , Edição de Genes/métodos , Genes Reporter , Células-Tronco Pluripotentes Induzidas/metabolismo , Sequência de Bases , Células Clonais , Criopreservação , Citometria de Fluxo , Humanos , Plasmídeos/genética , RNA Guia/metabolismo , Reprodutibilidade dos Testes , Análise de Célula Única , Transfecção
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