RESUMEN
Transmembrane protein 9 (TMEM9) is a transmembrane protein that regulates lysosomal acidification by interacting with the v-type ATPase complex. However, the role of TMEM9 in the lysosome-dependent autophagy machinery has yet to be identified. In this study, we demonstrate that the lysosomal protein TMEM9, which is involved in vesicle acidification, regulates Rab9-dependent alternative autophagy through its interaction with Beclin1. The cytosolic domain of TMEM9 interacts with Beclin1 via its Bcl-2-binding domain. This interaction between TMEM9 and Beclin1 dissociates Bcl-2, an autophagy-inhibiting partner, from Beclin1, thereby activating LC3-independent and Rab9-dependent alternative autophagy. Late endosomal and lysosomal TMEM9 apparently colocalizes with Rab9 but not with LC3. Furthermore, we show that multiple glycosylation of TMEM9, essential for lysosomal localization, is essential for its interaction with Beclin1 and the activation of Rab9-dependent alternative autophagy. These findings reveal that TMEM9 recruits and activates the Beclin1 complex at the site of Rab9-dependent autophagosome to induce alternative autophagy.
Asunto(s)
Autofagia , Beclina-1 , Lisosomas , Proteínas de la Membrana , Proteínas de Unión al GTP rab , Beclina-1/metabolismo , Humanos , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Proteínas de Unión al GTP rab/metabolismo , Lisosomas/metabolismo , Células HEK293 , Unión Proteica , Células HeLa , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Animales , Autofagosomas/metabolismoRESUMEN
Many cytokines produced by Kaposi's sarcoma-associated herpesvirus (KSHV)-infected cells have been shown to participate in the pathogenesis of KSHV. Determination of the exact role of cytokines in Kaposi's sarcoma (KS) pathogenesis is limited, however, by the difficulty to manipulate the target genes in human endothelial cells. In this study, we sought to elucidate the role of cytokines in KSHV-infected human immortalized endothelial cell line (HuARLT cells) by knockout (KO) of the corresponding target genes using the CRISPR/Cas9 system. The cytokine production profile of KSHV-infected HuARLT cells was analyzed using a protein array, and several cytokines were found to be highly upregulated following KSHV infection. This study focused on CXCL1, which was investigated by knocked out in HuARLT cells. KSHV-infected CXCL1 KO cells underwent increased cell death compared to KSHV-infected wild-type (WT) cells and mock-infected CXCL1 KO cells. Lytic replication was not observed in KSHV-infected WT nor CXCL1 KO cells. Phosphorylation of STAT3 was significantly suppressed in KSHV-infected CXCL1 KO cells. Additionally, inhibitors of STAT3 and CXCL1 induced cell death in KSHV-infected endothelial cells. Our results show that CXCL1 production is required for the survival of KSHV-infected endothelial cells, and the CXCL1 to STAT3 phosphorylation signaling pathway may be a therapeutic target for KS.
Asunto(s)
Herpesvirus Humano 8 , Sarcoma de Kaposi , Humanos , Herpesvirus Humano 8/fisiología , Células Endoteliales , Fosforilación , Citocinas/metabolismo , Quimiocina CXCL1/genética , Quimiocina CXCL1/metabolismo , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismoRESUMEN
Dengue virus, which belongs to the Flaviviridae family, can induce a range of symptoms from mild to severe, including dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. While infectious cloning technology is a useful tool for understanding viral pathogenesis and symptoms, it exhibits limitations when constructing the entire Flavivirus genome. The instability and toxicity of the genome to bacteria make its full-length construction in bacterial vectors a time-consuming and laborious process. To address these challenges, we employed the modified infectious subgenomic amplicon (ISA) method in this study, which can potentially be a superior tool for reverse genetic studies on the dengue virus. Using ISA, we generated recombinant dengue viruses de novo and validated their robust replication in both human and insect cell lines, which was comparable to that of the original strains. Moreover, the efficiency of ISA in genetically modifying the dengue virus was elucidated by successfully inserting the gene for green fluorescence protein into the genome of dengue virus serotype 4. Overall, this study highlighted the effectiveness of ISA for genetically engineering the dengue virus and provided a technical basis for a convenient reverse genetics system that could expedite investigations into the dengue virus.
Asunto(s)
Virus del Dengue , Dengue , Flaviviridae , Flavivirus , Humanos , Virus del Dengue/genética , Genética Inversa/métodos , Flavivirus/genética , Flaviviridae/genética , Replicación Viral/genéticaRESUMEN
With the rapid advances in biotechnological tools and strategies, microbial cell factory-constructing strategies have been established for the production of value-added compounds. However, optimizing the tradeoff between the biomass, yield, and titer remains a challenge in microbial production. Gene regulation is necessary to optimize and control metabolic fluxes in microorganisms for high-production performance. Various high-throughput genetic engineering tools have been developed for achieving rational gene regulation and genetic perturbation, diversifying the cellular phenotype and enhancing bioproduction performance. In this paper, we review the current high-throughput genetic engineering tools for gene regulation. In particular, technological approaches used in a diverse range of genetic tools for constructing microbial cell factories are introduced, and representative applications of these tools are presented. Finally, the prospects for high-throughput genetic engineering tools for gene regulation are discussed.
Asunto(s)
Biotecnología , Ingeniería Metabólica , Regulación de la Expresión Génica , Biomasa , Expresión GénicaRESUMEN
Klotho is a protein that plays different functions in female fertility. We have previously reported that klotho protein supplementation during in vitro maturation improves porcine embryo development, while klotho knockout for somatic cell cloning completely blocks full-term pregnancy in vivo. However, the effects of the microinjection of klotho protein or klotho knockdown dual vector in porcine embryos at different time points and the specific molecular mechanisms remain largely unknown. In this study, we injected the preassembled cas9 + sgRNA dual vector, for klotho knockdown, into the cytoplasm of the germinal vesicle stage of oocytes and into porcine embryos after 6-h parthenogenetic activation. Similarly, the klotho protein was inserted into the cytoplasm of germinal vesicle stage oocytes and porcine embryos after 6-h parthenogenetic activation. Compared with the controls, the microinjection of klotho dual vector markedly decreased the blastocyst formation rates in germinal vesicle stage oocytes and activated embryos. However, the efficiency of blastocyst formation when klotho protein was inserted before in vitro maturation was significantly higher than that after klotho protein insertion into parthenogenetically activated embryos. These results indicated that klotho knockdown may impair embryo development into blastocyst irrespective of injection timing. In addition, klotho protein injection timing in pig embryos may be an important factor for regulating embryo development.
Asunto(s)
Oocitos , ARN Guía de Sistemas CRISPR-Cas , Embarazo , Animales , Femenino , Porcinos , Oocitos/fisiología , Blastocisto , Desarrollo Embrionario/genética , PartenogénesisRESUMEN
Multiple host proteins affect the gene expression of Kaposi's sarcoma-associated herpesvirus (KSHV) during latent and lytic replication. High-mobility group box 1 (HMGB1) serves as a highly conserved chromosomal protein inside the cell and a prototypical damage-associated molecular pattern molecule outside the cell. HMGB1 has been shown to play a pathogenic role in viral infectious diseases and to regulate the lytic replication of KSHV. However, its functional effects on the KSHV life cycle in KSHV-infected cells have not been fully elucidated. Here, we explored the role of intracellular and extracellular HMGB1 in KSHV virion production by employing CRISPR/Cas9-mediated HMGB1 knockout in the KSHV-producing iSLK BAC16 cell line. Intracellular HMGB1 formed complexes with various proteins, and the abundance of HMGB1-interacting proteins changed during latent and lytic replication. Moreover, extracellular HMGB1 was found to enhance lytic replication by phosphorylating JNK. Of note, the expression of viral genes was attenuated during lytic replication in HMGB1 knockout iSLK BAC16 cells, with significantly decreased production of infectious virions compared to that of wild-type cells. Collectively, our results demonstrate that HMGB1 is an important cellular cofactor that affects the generation of infectious KSHV progeny during lytic replication. IMPORTANCE The high-mobility group box 1 (HMGB1) protein has many intra- and extracellular biological functions with an intricate role in various diseases. In certain viral infections, HMGB1 affects the viral life cycle and pathogenesis. In this study, we explored the effects of HMGB1 knockout on the production of Kaposi's sarcoma-associated herpesvirus (KSHV). HMGB1 knockout decreased virion production in KSHV-producing cells by decreasing the expression of viral genes. The processes by which HMGB1 affects KSHV production may occur inside or outside infected cells. For instance, several cellular and viral proteins interacted with intracellular HMGB1 in a nucleosomal complex, whereas extracellular HMGB1 induced JNK phosphorylation, thereby enhancing lytic replication. Our results suggest that both intracellular and extracellular HMGB1 are necessary for efficient KSHV replication. Thus, HMGB1 may represent an effective therapeutic target for the regulation of KSHV production.
Asunto(s)
Regulación Viral de la Expresión Génica , Proteína HMGB1/metabolismo , Herpesvirus Humano 8/fisiología , Virión/metabolismo , Línea Celular Tumoral , Técnicas de Inactivación de Genes , Proteína HMGB1/genética , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/metabolismo , Humanos , Nucleosomas/metabolismo , Regiones Promotoras Genéticas , Transducción de Señal , Proteínas Virales/genética , Activación Viral , Replicación ViralRESUMEN
Efficient control over multiple gene expression still presents a major challenge. Synthetic sRNA enables targeted gene expression control in trans without directly modifying the chromosome, but its use to simultaneously target multiple genes can often cause cell growth defects because of the need for additional energy for transcription and lowering of their repression efficiency by limiting the amount of Hfq protein. To address these limitations, we present fusion sRNA (fsRNA) that simultaneously regulates the translation of multiple genes efficiently. It is constructed by linking the mRNA-binding modules for multiple targeted genes in one sRNA scaffold via one-pot generation using overlap extension PCR. The repression capacity of fsRNA was demonstrated by the construction of sRNAs to target four endogenous genes: caiF, hybG, ytfR and minD in Escherichia coli. Their cross-reactivity and the effect on cell growth were also investigated. As practical applications, we applied fsRNA to violacein- and protocatechuic acid-producing strains, resulting in increases of 13% violacein and 81% protocatechuic acid, respectively. The developed fsRNA-mediated multiple gene expression regulation system thus enables rapid and efficient development of optimised cell factories for valuable chemicals without cell growth defects and limiting cellular resources.Key points⢠Synthetic fusion sRNA (fsRNA)-based system was constructed for the repression of multiple target genes.⢠fsRNA repressed multiple genes by only expressing a single sRNA while minimising the cellular burden.⢠The application of fsRNA showed the increased production titers of violacein (13%) and protocatechuic acid (81%).
Asunto(s)
Proteínas de Escherichia coli , ARN Pequeño no Traducido , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Proteína de Factor 1 del Huésped/genética , Chaperonas Moleculares/metabolismo , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , ARN Pequeño no Traducido/genéticaRESUMEN
Mitochondrial quality control maintains mitochondrial function by regulating mitochondrial dynamics and mitophagy. Despite the identification of mitochondrial quality control factors, little is known about the crucial regulators coordinating both mitochondrial fission and mitophagy. Through a cell-based functional screening assay, FK506 binding protein 8 (FKBP8) was identified to target microtubule-associated protein 1 light chain 3 (LC3) to the mitochondria and to change mitochondrial morphology. Microscopy analysis revealed that the formation of tubular and enlarged mitochondria was observed in FKBP8 knockdown HeLa cells and the cortex of Fkbp8 heterozygote-knockout mouse embryos. Under iron depletion-induced stress, FKBP8 was recruited to the site of mitochondrial division through budding and colocalized with LC3. FKBP8 was also found to be required for mitochondrial fragmentation and mitophagy under hypoxic stress. Conversely, FKBP8 overexpression induced mitochondrial fragmentation in HeLa cells, human fibroblasts and mouse embryo fibroblasts (MEFs), and this fragmentation occurred in Drp1 knockout MEF cells, FIP200 knockout HeLa cells and BNIP3/NIX double knockout HeLa cells, but not in Opa1 knockout MEFs. Interestingly, we found an LIR motif-like sequence (LIRL), as well as an LIR motif, at the N-terminus of FKBP8 and LIRL was essential for both inducing mitochondrial fragmentation and binding of FKBP8 to OPA1. Together, we suggest that FKBP8 plays an essential role in mitochondrial fragmentation through LIRL during mitophagy and this activity of FKBP8 together with LIR is required for mitophagy under stress conditions.
Asunto(s)
Fibroblastos/metabolismo , Mitocondrias/metabolismo , Dinámicas Mitocondriales , Estrés Fisiológico , Proteínas de Unión a Tacrolimus/metabolismo , Animales , Células HEK293 , Células HeLa , Humanos , Ratones , Ratones Noqueados , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Mitocondrias/genética , Proteínas de Unión a Tacrolimus/genéticaRESUMEN
Malonyl-CoA is an important central metabolite for the production of diverse valuable chemicals including natural products, but its intracellular availability is often limited due to the competition with essential cellular metabolism. Several malonyl-CoA biosensors have been developed for high-throughput screening of targets increasing the malonyl-CoA pool. However, they are limited for use only in Escherichia coli and Saccharomyces cerevisiae and require multiple signal transduction steps. Here we report development of a colorimetric malonyl-CoA biosensor applicable in three industrially important bacteria: E. coli, Pseudomonas putida, and Corynebacterium glutamicum RppA, a type III polyketide synthase producing red-colored flaviolin, was repurposed as a malonyl-CoA biosensor in E. coli Strains with enhanced malonyl-CoA accumulation were identifiable by the colorimetric screening of cells showing increased red color. Other type III polyketide synthases could also be repurposed as malonyl-CoA biosensors. For target screening, a 1,858 synthetic small regulatory RNA library was constructed and applied to find 14 knockdown gene targets that generally enhanced malonyl-CoA level in E. coli These knockdown targets were applied to produce two polyketide (6-methylsalicylic acid and aloesone) and two phenylpropanoid (resveratrol and naringenin) compounds. Knocking down these genes alone or in combination, and also in multiple different E. coli strains for two polyketide cases, allowed rapid development of engineered strains capable of enhanced production of 6-methylsalicylic acid, aloesone, resveratrol, and naringenin to 440.3, 30.9, 51.8, and 103.8 mg/L, respectively. The malonyl-CoA biosensor developed here is a simple tool generally applicable to metabolic engineering of microorganisms to achieve enhanced production of malonyl-CoA-derived chemicals.
Asunto(s)
Proteínas Bacterianas , Técnicas Biosensibles/métodos , Corynebacterium glutamicum , Escherichia coli , Malonil Coenzima A/análisis , Ingeniería Metabólica , Sintasas Poliquetidas , Pseudomonas putida , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Corynebacterium glutamicum/enzimología , Corynebacterium glutamicum/genética , Escherichia coli/enzimología , Escherichia coli/genética , Sintasas Poliquetidas/genética , Sintasas Poliquetidas/metabolismo , Pseudomonas putida/enzimología , Pseudomonas putida/genéticaRESUMEN
Localized surface plasmon resonance (LSPR)-based biosensors have recently garnered increasing attention due to their potential to allow label-free, portable, low-cost, and real-time monitoring of diverse analytes. Recent developments in this technology have focused on biochemical markers in clinical and environmental settings coupled with advances in nanostructure technology. Therefore, this review focuses on the recent advances in LSPR-based biosensor technology for the detection of diverse chemicals and biomolecules. Moreover, we also provide recent examples of sensing strategies based on diverse nanostructure platforms, in addition to their advantages and limitations. Finally, this review discusses potential strategies for the development of biosensors with enhanced sensing performance.
RESUMEN
Exposure to particulate matter (PM) is becoming a major global health issue. The amount and time of exposure to PM are known to be closely associated with cardiovascular diseases. However, the mechanism through which PM affects the vascular system is still not clear. Endothelial cells line the interior surface of blood vessels and actively interact with plasma proteins, including the complement system. Unregulated complement activation caused by invaders, such as pollutants, may promote endothelial inflammation. In the present study, we sought to investigate whether urban PM (UPM) acts on the endothelial environment via the complement system. UPM-treated human endothelial cells with normal human serum showed the deposition of membrane attack complexes (MACs) on the cell surface via the alternative pathway of the complement system. Despite the formation of MACs, cell death was not observed, and cell proliferation was increased in UPM-mediated complement activation. Furthermore, complement activation on endothelial cells stimulated the production of inflammation-related proteins. Our results revealed that UPM could activate the complement system in human endothelial cells and that complement activation regulated inflammatory reaction in microenvironment. These findings provide clues with regard to the role of the complement system in pathophysiologic events of vascular disease elicited by air pollution.
Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Activación de Complemento , Proteínas del Sistema Complemento/metabolismo , Células Endoteliales/metabolismo , Inflamación/metabolismo , Vasos Sanguíneos/patología , Muerte Celular , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Citocinas/metabolismo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Material Particulado/efectos adversos , Fosforilación , Especies Reactivas de Oxígeno/metabolismo , Factor de Transcripción STAT3/metabolismoRESUMEN
Aptamers are artificial nucleic acid ligands that have been employed in various fundamental studies and applications, such as biological analyses, disease diagnostics, targeted therapeutics, and environmental pollutant detection. This review focuses on the recent advances in aptamer discovery strategies that have been used to detect various chemicals and biomolecules. Recent examples of the strategies discussed here are based on the classification of these micro/nanomaterial-mediated systematic evolution of ligands by exponential enrichment (SELEX) platforms into three categories: bead-mediated, carbon-based nanomaterial-mediated, and other nanoparticle-mediated strategies. In addition to describing the advantages and limitations of the aforementioned strategies, this review discusses potential strategies to develop high-performance aptamers.
Asunto(s)
Aptámeros de Nucleótidos/química , Nanopartículas/química , Nanoestructuras/química , Humanos , LigandosRESUMEN
PURPOSE: A linear valve-like structure at the pulmonary artery terminus is identified on CT in some patients with patent ductus arteriosus (PDA) and can potentially be mistaken for endarteritis. The purpose of this study was to evaluate the differences in CT features between adult patients with PDA and a linear structure and those without. MATERIALS AND METHODS: We retrospectively evaluated ECG-gated cardiac CT of 38 patients with PDA dividing them into two groups [patients with linear symmetrical valve-like structure (group1, n = 16), and those without (group 2, n = 22)]. We analyzed CT findings of the PDA including length, minimal and maximal diameter, presence of calcification, and PDA type, comparing the two subgroups. The authors also investigated the prevalence of endarteritis. RESULTS: There was no difference in CT findings between the two groups in the prevalence of calcification and length, and minimal and maximal diameter of PDA. Notably the linear valve-like structure was only identified in type 1 PDA (cone-shaped PDA) (p = 0.04), while there were variable types of PDA in group 2. There was only one case of endarteritis as a complication of PDA in group 1. In contrast to a linear valve-like structure, asymmetrical nodular thickening was noted in the patient with endarteritis on CT overlying the pre-existing linear valve-like structure at the pulmonary end of PDA. CONCLUSION: A linear valve-like structure is frequently identified at the pulmonary end in type 1 PDA. This CT finding should not be mistaken for endarteritis in the absence of other clinical evidence.
Asunto(s)
Conducto Arterioso Permeable/diagnóstico , Endarteritis/diagnóstico , Arteria Pulmonar/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Conducto Arterioso Permeable/patología , Ecocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Arteria Pulmonar/patología , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Adulto JovenRESUMEN
Biosensor devices are important in clinical practice and environmental studies because they allow specific detection of target molecules from a variety of samples. However, challenges still remain when attempting to develop sensitive, selective, rapid, and cost-effective assays for biomolecule detection. Devices that use DNA-modifying enzymes to catalyze detection reactions have recently been developed. These devices show promise because they are often more sensitive and specific, have shorter assay times, are more cost-effective, and are easier to use than the currently used biosensors. Here, we review the current trends in DNA-modifying enzyme reaction-coupled biosensors, including devices using DNA polymerases, nicking endonuclease, exonucleases, and ligases. The molecular strategies underlying diverse DNA-modifying enzymes coupled to biomolecule detection platforms are reviewed. We also discuss the strengths and limitations of each strategy and suggest methods to overcome current limitations. Finally, the future prospects of DNA-modifying enzyme reaction-coupled biosensor development have been proposed.
Asunto(s)
Técnicas Biosensibles , ADN Ligasas , ADN Polimerasa Dirigida por ADN , Técnicas de Diagnóstico Molecular , HumanosRESUMEN
BACKGROUND: Some researchers have reported that applying compression closer to the maximum diameter of the left ventricle (Point_max.LV) is associated with worse clinical outcomes, challenging its traditional position as optimum compression point (Point_optimum). By locating the mid-sternum (the actual compression site) in terms of Point_max.LV and its right ventricular equivalent (Point_max.RV), we aimed to determine its optimum horizontal position associated with increased chances of return of spontaneous circulation (ROSC). METHODS: A retrospective, cross-sectional study was performed at a university hospital from 2014 to 2019 on non-traumatic out-of-hospital cardiac arrest (OHCA) victims who underwent chest computed tomography. On absolute x-axis, we designated the x-coordinate of the mid-sternum (x_mid-sternum) as 0 and leftward direction as positive. Re-defining the x-coordinate of Point_max.RV and Point_max.LV as 0 and 1 interventricular unit (IVU), respectively, we could convert x_mid-sternum to "-x_max.RV/(x_max.LV - x_max.RV) (IVU)." Using multiple logistic regression analysis, we investigated whether this converted x_mid-sternum was associated with clinical outcomes, adjusting core elements of the Utstein template. RESULTS: Among 887 non-traumatic OHCA victims, 124 [64.4 ± 16.7 years, 43 women (34.7%)] were enrolled. Of these, 80 (64.5%) exhibited ROSC. X_mid-sternum ranging from -1.71 to 0.58 (-0.36 ± 0.38) IVU was categorised into quintiles: <-0.60, -0.60 to -0.37, -0.37 to -0.22, -0.22 to -0.07 and ≥-0.07 (reference) IVU. The first quintile was positively associated with ROSC (odds ratio [95% confidence interval], 9.43 [1.44, 63.3]). CONCLUSION: Point_optimum might be located far rightwards to Point_max.RV, challenging the traditional assumption identifying Point_optimum as Point_max.LV.
Asunto(s)
Reanimación Cardiopulmonar/métodos , Ventrículos Cardíacos/anatomía & histología , Paro Cardíaco Extrahospitalario/terapia , Esternón/anatomía & histología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía Torácica , Estudios Retrospectivos , Tomografía Computarizada por Rayos XRESUMEN
The demyelinating diseases of the central nervous system involve myelin abnormalities, oligodendrocyte damage, and consequent glia activation. Neurotoxicant cuprizone (CPZ) was used to establish a mouse model of demyelination. However, the effects of CPZ on microRNA (miRNA) expression and behavior have not been clearly reported. We analyzed the behavior of mice administered a diet containing 0.2% CPZ for 6 weeks, followed by 6 weeks of recovery. Rotarod analysis demonstrated that the treated group had poorer motor coordination than control animals. This effect was reversed after 6 weeks of CPZ withdrawal. Open-field tests showed that CPZ-treated mice exhibited significantly increased anxiety and decreased exploratory behavior. CPZ-induced demyelination was observed to be alleviated after 4 weeks of CPZ treatment, according to luxol fast blue (LFB) staining and myelin basic protein (MBP) expression. miRNA expression profiling showed that the expression of 240 miRNAs was significantly changed in CPZ-fed mice compared with controls. Furthermore, miR-155-5p and miR-20a-5p upregulations enhanced NgR induction through Smad 2 and Smad 4 suppression in demyelination. Taken together, our results demonstrate that CPZ-mediated demyelination induces behavioral deficits with apparent alterations in miRNA expression, suggesting that differences in miRNA expression in vivo may be new potential therapeutic targets for remyelination.
Asunto(s)
Cuprizona/efectos adversos , Enfermedades Desmielinizantes/psicología , Conducta Exploratoria/efectos de los fármacos , Redes Reguladoras de Genes/efectos de los fármacos , Animales , Enfermedades Desmielinizantes/inducido químicamente , Enfermedades Desmielinizantes/genética , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , MicroARNs/efectos de los fármacos , MicroARNs/genética , Prueba de Desempeño de Rotación con Aceleración ConstanteRESUMEN
Synthetic small regulatory RNA (sRNA) can efficiently downregulate target gene expression at translational level in metabolic engineering, but cannot be used in engineered strain already having incompatible plasmid(s). To address this problem and make the sRNA gene expression modulation platform universally applicable, we report the development and applications of expanded synthetic sRNA expression platforms for rapid, multiplexed and genome-scale target gene knockdown in engineered Escherichia coli. As proof-of-concept, high performance strains capable of producing L-proline (54.1â¯gâ¯l-1) and L-threonine (22.9â¯gâ¯l-1) are rapidly developed by combinatorial knockdown of up to three genes via one-step co-transformation of sRNA expression vectors. Furthermore, a genome-scale sRNA library targeting 1,858 E. coli genes is employed to construct crude violacein (5.19â¯gâ¯l-1) and indigo (135â¯mgâ¯l-1) producers by high-throughput colorimetric screening. These examples demonstrate that the expanded sRNA expression vectors developed here enables rapid development of chemical overproducers regardless of plasmid compatibility.
Asunto(s)
Escherichia coli , Regulación Bacteriana de la Expresión Génica , Técnicas de Silenciamiento del Gen , ARN Bacteriano , ARN Interferente Pequeño , Escherichia coli/genética , Escherichia coli/metabolismo , Plásmidos/genética , Plásmidos/metabolismo , ARN Bacteriano/biosíntesis , ARN Bacteriano/genética , ARN Interferente Pequeño/biosíntesis , ARN Interferente Pequeño/genéticaRESUMEN
The uptake of exogenous DNA materials through the cell membrane by bacteria, known as transformation, is essential for the genetic manipulation of bacteria and, thus, plays key roles in biotechnological and biological research. The efficiency of natural transformation is very low; therefore, various artificial transformation methods have been developed for simple and efficient bacterial transformation. The basic bacterial transformation method is based on chemical, physical, and electrical processes and other means to permeabilize the bacterial cell membrane to allow plasmid DNA uptake. With the introduction of novel chemicals, materials, and devices and the optimization of protocols, new transformation methods have become simpler, cheaper, and more reproducible for use in diverse bacterial species compared with conventional methods. In this review, artificial transformation methods have been classified according to the membrane-permeabilizing mechanisms employed by them. Their influential factors, transformation efficiency, advantages, disadvantages, and practical applications are briefly illustrated. Finally, physicochemical transformation as a new bacterial transformation technique has also been described.
Asunto(s)
Bacterias/genética , Plásmidos/genética , Transformación Bacteriana , Transformación Genética , ADN Bacteriano/genética , Microorganismos Modificados GenéticamenteRESUMEN
OBJECTIVES: To evaluate the clinical significance of discrepant lesions between coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) in a longitudinal study. METHODS: In 220 patients with suspected coronary artery disease (CAD) who underwent both 256-row CCTA and ICA, the obstructive CAD (≥ 50% stenosis) on CCTA was compared with that on ICA as the reference standard. We analysed the causes of the discrepancy between CCTA and ICA. During a 40-month follow-up period, major adverse cardiac events (MACE) were assessed. RESULTS: Discordance between CCTA and ICA was observed in 121 of the 3166 coronary artery segments (3.8%). Common causes were calcification (45.9%) and positive remodelling (PR) (29.6%) in 83 false positive lesions, and noise (40.0%) and motion artefact (37.8%) in 38 false negative lesions. MACE occurred in seven lesions among the discrepant lesions; six among the 29 PR lesions (20.7%) and one among the 53 calcified lesions (1.9%). With respect to the prediction power of MACE in an intermediate stenosis, the CCTA-related value including PR was higher than the ICA-related value. CONCLUSIONS: PR was a frequent cause of MACE among the false positive lesions on CCTA. Therefore, the presence of PR on CCTA may suggest clinical significance, although it can be missed by ICA. KEY POINTS: ⢠Compared to ICA, PR in CCTA may be cause of false positive lesion. ⢠CCTA-related value including PR shows higher prediction power of MACE than ICA-related value. ⢠PR reflects atherosclerotic burden that can be related to cardiac events. ⢠PR in CCTA should be observed carefully, even if it is false positive.
Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Radiografía Intervencional/métodos , Estenosis Coronaria/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los ResultadosRESUMEN
In neurodegenerative diseases like Alzheimer's disease (AD), tau is hyperphosphorylated and forms aggregates and neurofibrillary tangles in affected neurons. Autophagy is critical to clear the aggregates of disease-associated proteins and is often altered in patients and animal models of AD. Because mechanistic target of rapamycin (mTOR) negatively regulates autophagy and is hyperactive in the brains of patients with AD, mTOR is an attractive therapeutic target for AD. However, pharmacological strategies to increase autophagy by targeting mTOR inhibition cause various side effects. Therefore, autophagy activation mediated by non-mTOR pathways is a new option for autophagy-based AD therapy. Here, we report that pimozide activates autophagy to rescue tau pathology in an AD model. Pimozide increased autophagic flux through the activation of the AMPK-Unc-51 like autophagy activating kinase 1 (ULK1) axis, but not of mTOR, in neuronal cells, and this function was independent of dopamine D2 receptor inhibition. Pimozide reduced levels of abnormally phosphorylated tau aggregates in neuronal cells. Further, daily intraperitoneal (i.p.) treatment of pimozide led to a recovery from memory deficits of TauC3 mice expressing a caspase-cleaved form of tau. In the brains of these mice, we found increased phosphorylation of AMPK1 and ULK1, and reduced levels of the soluble oligomers and NP40-insoluble aggregates of abnormally phosphorylated tau. Together, these results suggest that pimozide rescues memory impairments in TauC3 mice and reduces tau aggregates by increasing autophagic flux through the mTOR-independent AMPK-ULK1 axis.