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2.
bioRxiv ; 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37609293

RESUMEN

Uterine leiomyoma or fibroids are the most common prevalent noncancerous tumors of the uterine muscle layer. Common symptoms associated with fibroids include pelvic pain, heavy menstrual bleeding, anemia, and pelvic pressure. These tumors are a leading cause of gynecological care but lack long-term therapy as the origin and development of fibroids are not well understood. Several next-generation sequencing technologies have been performed to identify the underlying genetic and epigenetic basis of fibroids. However, there remains a systemic gap in our understanding of molecular and biological process that define uterine fibroids. Recent epitranscriptomics studies have unraveled RNA modifications that are associated with all forms of RNA and are thought to influence both normal physiological functions and the progression of diseases. We quantified RNA expression profiles by analyzing publicly available RNA-seq data for 15 known epigenetic mediators to identify their expression profile in uterine fibroids compared to myometrium. To validate our findings, we performed RT-qPCR on a separate cohort of uterine fibroids targeting these modifiers confirming our RNA-seq data. We then examined protein profiles of key m6A modifiers in fibroids and their matched myometrium. In concordance with our RNA expression profiles, no significant differences were observed in these proteins in uterine fibroids compared to myometrium. To determine abundance of RNA modifications, mRNA and small RNA from fibroids and matched myometrium were analyzed by UHPLC MS/MS. In addition to the prevalent N6-methyladenosine (m6A), we identified 11 other known modifiers but did not identify any aberrant expression in fibroids. We then mined a previously published dataset and identified differential expression of m6A modifiers that were specific to fibroid genetic sub-type. Our analysis also identified m6A consensus motifs on genes previously identified to be dysregulated in uterine fibroids. Overall, using state-of-the-art mass spectrometry, RNA expression and protein profiles, we characterized and identified differentially expressed m6A modifiers in relation to driver mutations. Despite the use of several different approaches, we identified limited differential expression of RNA modifiers and associated modifications in uterine fibroids. However, considering the highly heterogenous genomic and cellular nature of fibroids, and the possible contribution of single molecule m6A modifications to fibroid pathology, there is a need for greater in-depth characterization of m6A marks and modifiers in a larger and varied patient cohort.

3.
Sci Adv ; 9(19): eade7500, 2023 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-37163588

RESUMEN

A fundamental feature of cell signaling is the conversion of extracellular signals into adaptive transcriptional responses. The role of RNA modifications in this process is poorly understood. The small nuclear RNA 7SK prevents transcriptional elongation by sequestering the cyclin dependent kinase 9/cyclin T1 (CDK9/CCNT1) positive transcription elongation factor (P-TEFb) complex. We found that epidermal growth factor signaling induces phosphorylation of the enzyme methyltransferase 3 (METTL3), leading to METTL3-mediated methylation of 7SK. 7SK methylation enhanced its binding to heterogeneous nuclear ribonucleoproteins, causing the release of the HEXIM1 P-TEFb complex subunit1 (HEXIM1)/P-TEFb complex and inducing transcriptional elongation. Our findings establish the mechanism underlying 7SK activation and uncover a previously unknown function for the m6A modification in converting growth factor signaling events into a regulatory transcriptional response via an RNA methylation-dependent switch.


Asunto(s)
Factor B de Elongación Transcripcional Positiva , Proteínas de Unión al ARN , Humanos , Metilación , Metiltransferasas/genética , Metiltransferasas/metabolismo , Factor B de Elongación Transcripcional Positiva/genética , Factor B de Elongación Transcripcional Positiva/metabolismo , ARN Nuclear Pequeño/genética , ARN Nuclear Pequeño/metabolismo , Proteínas de Unión al ARN/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcripción Genética
4.
Curr Issues Mol Biol ; 46(1): 244-261, 2023 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-38248319

RESUMEN

Thirty percent of all mutations causing human disease generate mRNAs with premature termination codons (PTCs). Recognition and degradation of these PTC-containing mRNAs is carried out by the mechanism known as nonsense-mediated mRNA decay (NMD). Upf2 is a scaffold protein known to be a central component of the NMD surveillance pathway. It harbors three middle domains of eukaryotic initiation factor 4G (mIF4G-1, mIF4G-2, mIF4G-3) in its N-terminal region that are potentially important in regulating the surveillance pathway. In this study, we defined regions within the mIF4G-1 and mIF4G-2 that are required for proper function of Upf2p in NMD and translation termination in Saccharomyces cerevisiae. In addition, we narrowed down the activity of these regions to an aspartic acid (D59) in mIF4G-1 that is important for NMD activity and translation termination accuracy. Taken together, these studies suggest that inherently charged residues within mIF4G-1 of Upf2p play a role in the regulation of the NMD surveillance mechanism in S. cerevisiae.

5.
Nucleic Acids Res ; 50(16): 9306-9318, 2022 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-35979951

RESUMEN

Failure to prevent accumulation of the non-canonical nucleotide inosine triphosphate (ITP) by inosine triphosphate pyrophosphatase (ITPase) during nucleotide synthesis results in misincorporation of inosine into RNA and can cause severe and fatal developmental anomalies in humans. While the biochemical activity of ITPase is well understood, the pathogenic basis of ITPase deficiency and the molecular and cellular consequences of ITP misincorporation into RNA remain cryptic. Here, we demonstrate that excess ITP in the nucleotide pool during in vitro transcription results in T7 polymerase-mediated inosine misincorporation in luciferase RNA. In vitro translation of inosine-containing luciferase RNA reduces resulting luciferase activity, which is only partly explained by reduced abundance of the luciferase protein produced. Using Oxford Nanopore Direct RNA sequencing, we reveal inosine misincorporation to be stochastic but biased largely towards misincorporation in place of guanosine, with evidence for misincorporation also in place of cytidine, adenosine and uridine. Inosine misincorporation into RNA is also detected in Itpa-null mouse embryonic heart tissue as an increase in relative variants compared with the wild type using Illumina RNA sequencing. By generating CRISPR/Cas9 rat H9c2 Itpa-null cardiomyoblast cells, we validate a translation defect in cells that accumulate inosine within endogenous RNA. Furthermore, we observe hindered cellular translation of transfected luciferase RNA containing misincorporated inosine in both wild-type and Itpa-null cells. We therefore conclude that inosine misincorporation into RNA perturbs translation, thus providing mechanistic insight linking ITPase deficiency, inosine accumulation and pathogenesis.


Asunto(s)
Inosina Trifosfato , ARN , Humanos , Animales , Ratones , Ratas , Inosina Trifosfato/metabolismo , Pirofosfatasas/genética , Inosina , Nucleótidos
6.
Genes (Basel) ; 13(3)2022 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-35327975

RESUMEN

Epitranscriptomic marks, in the form of enzyme catalyzed RNA modifications, play important gene regulatory roles in response to environmental and physiological conditions. However, little is known with respect to how acute toxic doses of pharmaceuticals influence the epitranscriptome. Here we define how acetaminophen (APAP) induces epitranscriptomic reprogramming and how the writer Alkylation Repair Homolog 8 (Alkbh8) plays a key gene regulatory role in the response. Alkbh8 modifies tRNA selenocysteine (tRNASec) to translationally regulate the production of glutathione peroxidases (Gpx's) and other selenoproteins, with Gpx enzymes known to play protective roles during APAP toxicity. We demonstrate that APAP increases toxicity and markers of damage, and decreases selenoprotein levels in Alkbh8 deficient mouse livers, when compared to wildtype. APAP also promotes large scale reprogramming of many RNA marks comprising the liver tRNA epitranscriptome including: 5-methoxycarbonylmethyluridine (mcm5U), isopentenyladenosine (i6A), pseudouridine (Ψ), and 1-methyladenosine (m1A) modifications linked to tRNASec and many other tRNA's. Alkbh8 deficiency also leads to wide-spread epitranscriptomic dysregulation in response to APAP, demonstrating that a single writer defect can promote downstream changes to a large spectrum of RNA modifications. Our study highlights the importance of RNA modifications and translational responses to APAP, identifies writers as key modulators of stress responses in vivo and supports the idea that the epitranscriptome may play important roles in responses to pharmaceuticals.


Asunto(s)
Acetaminofén , ARN de Transferencia , Homólogo 8 de AlkB ARNt Metiltransferasa/genética , Animales , Ratones , Preparaciones Farmacéuticas , ARN , ARN de Transferencia/genética , Selenoproteínas
7.
Front Pharmacol ; 12: 652989, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34248618

RESUMEN

Grona styracifolia (Osbeck) Merr. (GS), a popular folk medicine, is clinically applied to treat nephrolithiasis. In this study, a urinary metabolic analysis was performed in a mouse model of renal calcium oxalate (CaOx) crystal deposition to identify the differentially altered metabolites in mice with oxalate-induced renal injury and explore the therapeutic mechanisms of GS against nephrolithiasis. Twenty-four mice were randomly divided into the control, oxalate and GS-treated groups. A metabolomics approach based on ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) was used to analyze the metabolic profiles of the urine samples. In addition, network pharmacology analysis was performed with different databases. As a result, the protective effects of GS were verified by measuring biochemical parameters and detecting crystal deposition. Fifteen metabolites were identified as the differentially altered metabolites in mice with crystal-induced renal injury. Most were involved in amino acid and fatty acid metabolism. Thirteen of these metabolites showed a reversal trend following GS treatment. A component-target-metabolite network was further constructed and nine overlapping target proteins of GS and the differentially altered metabolites were discovered. Among these proteins, the expression of estrogen receptor 2 (ESR2) in renal tissues was significantly down-regulated while androgen receptor (AR) expression was obviously increased in the oxalate group compared with the control group. These changes were reversed by the GS treatment. In conclusion, GS exerts its therapeutic effect by regulating multiple metabolic pathways and the expression of ESR and AR in mice with oxalate-induced renal injury.

8.
Biochemistry ; 60(24): 1885-1895, 2021 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-34081430

RESUMEN

NMR spectroscopy was used to investigate the phenomenon of ribosome-amplified metabolism or RAMBO between pyruvate kinase and ribosomes. Because the concentration of ribosomes increases as the cell grows, ribosome binding interactions may regulate metabolic fluxes by altering the distribution of bound and free enzymes. Pyruvate kinase (PK) catalyzes the last step of glycolysis and represents a major drug target for controlling bacterial infections. The binding of metabolic enzymes to ribosomes creates protein quinary structures with altered catalytic activities. NMR spectroscopy and chemical cross-linking combined with high-resolution mass spectrometry were used to establish that PK binds to ribosome at three independent sites, the L1 stalk, the A site, and the mRNA entry pore. The bioanalytical methodology described characterizes the altered kinetics and confirms the specificity of pyruvate kinase-ribosome interaction, affording an opportunity to investigate the ribosome dependence of metabolic reactions under solution conditions that closely mimic the cytosol. Expanding on the concept of ribosomal heterogeneity, which describes variations in ribosomal constituents that contribute to the specificity of cellular processes, this work firmly establishes the reciprocal process by which ribosome-dependent quinary interactions affect metabolic activity.


Asunto(s)
Piruvato Quinasa/metabolismo , Ribosomas/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Geobacillus stearothermophilus/metabolismo , Glucólisis/fisiología , Cinética , Espectroscopía de Resonancia Magnética/métodos , Unión Proteica/fisiología , ARN Mensajero/metabolismo , Proteínas Ribosómicas/metabolismo
9.
Proc Natl Acad Sci U S A ; 118(2)2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-33397721

RESUMEN

Self-splicing proteins, called inteins, are present in many human pathogens, including the emerging fungal threats Cryptococcus neoformans (Cne) and Cryptococcus gattii (Cga), the causative agents of cryptococcosis. Inhibition of protein splicing in Cryptococcus sp. interferes with activity of the only intein-containing protein, Prp8, an essential intron splicing factor. Here, we screened a small-molecule library to find addititonal, potent inhibitors of the Cne Prp8 intein using a split-GFP splicing assay. This revealed the compound 6G-318S, with IC50 values in the low micromolar range in the split-GFP assay and in a complementary split-luciferase system. A fluoride derivative of the compound 6G-318S displayed improved cytotoxicity in human lung carcinoma cells, although there was a slight reduction in the inhibition of splicing. 6G-318S and its derivative inhibited splicing of the Cne Prp8 intein in vivo in Escherichia coli and in C. neoformans Moreover, the compounds repressed growth of WT C. neoformans and C. gattii In contrast, the inhibitors were less potent at inhibiting growth of the inteinless Candida albicans Drug resistance was observed when the Prp8 intein was overexpressed in C. neoformans, indicating specificity of this molecule toward the target. No off-target activity was observed, such as inhibition of serine/cysteine proteases. The inhibitors bound covalently to the Prp8 intein and binding was reduced when the active-site residue Cys1 was mutated. 6G-318S showed a synergistic effect with amphotericin B and additive to indifferent effects with a few other clinically used antimycotics. Overall, the identification of these small-molecule intein-splicing inhibitors opens up prospects for a new class of antifungals.


Asunto(s)
Empalme de Proteína/fisiología , Proteínas de Unión al ARN/genética , Antifúngicos/farmacología , Cryptococcus neoformans/genética , Cryptococcus neoformans/metabolismo , Cryptococcus neoformans/patogenicidad , Proteínas Fúngicas/metabolismo , Humanos , Inteínas/genética , Intrones/genética , Empalme de Proteína/genética , Empalme del ARN/genética , Proteínas de Unión al ARN/metabolismo , Alineación de Secuencia/métodos
10.
Free Neuropathol ; 22021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37284625

RESUMEN

Heart disease is an integral part of Friedreich ataxia (FA) and the most common cause of death in this autosomal recessive disease. The result of the mutation is lack of frataxin, a small mitochondrial protein. The clinical and pathological phenotypes of FA are complex, involving brain, spinal cord, dorsal root ganglia, sensory nerves, heart, and endocrine pancreas. The hypothesis is that frataxin deficiency causes downstream changes in the proteome of the affected tissues, including the heart. A proteomic analysis of heart proteins in FA cardiomyopathy by antibody microarray, Western blots, immunohistochemistry, and double-label laser scanning confocal immunofluorescence microscopy revealed upregulation of desmin and its chaperone protein, αB-crystallin. In normal hearts, these two proteins are co-localized at intercalated discs and Z discs. In FA, desmin and αB-crystallin aggregate, causing chaotic modification of intercalated discs, clustering of mitochondria, and destruction of the contractile apparatus of cardiomyocytes. Western blots of tissue lysates in FA cardiomyopathy reveal a truncated desmin isoprotein that migrates at a lower molecular weight range than wild type desmin. While desmin and αB-crystallin are not mutated in FA, the accumulation of these proteins in FA hearts allows the conclusion that FA cardiomyopathy is a desminopathy akin to desmin myopathy of skeletal muscle.

11.
Curr Protoc Nucleic Acid Chem ; 82(1): e113, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32822120

RESUMEN

This article describes a protocol for detecting and quantifying RNA phosphorothioate modifications in cellular RNA samples. Starting from solid-phase synthesis of phosphorothioate RNA dinucleotides, followed by purification with reversed-phase HPLC, phosphorothioate RNA dinucleotide standards are prepared for UPLC-MS and LC-MS/MS methods. RNA samples are extracted from cells using TRIzol reagent, then digested with a nuclease mixture and analyzed by mass spectrometry. UPLC-MS is employed first to identify RNA phosphorothioate modifications. An optimized LC-MS/MS method is then employed to quantify the frequency of RNA phosphorothioate modifications in a series of model cells. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Synthesis, purification, and characterization of RNA phosphorothioate dinucleotides Basic Protocol 2: Digestion of RNA samples extracted from cells Basic Protocol 3: Detection and quantification of RNA phosphorothioate modifications by mass spectrometry.


Asunto(s)
Espectrometría de Masas/métodos , Oligonucleótidos Fosforotioatos/química , ARN/química , Animales , Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Fase Inversa/métodos , Escherichia coli/genética , Humanos , Lactobacillus/genética , Oligonucleótidos Fosforotioatos/aislamiento & purificación , Control de Calidad , ARN/aislamiento & purificación , Estándares de Referencia , Técnicas de Síntesis en Fase Sólida/métodos
12.
Nature ; 583(7817): 638-643, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32555463

RESUMEN

N4-acetylcytidine (ac4C) is an ancient and highly conserved RNA modification that is present on tRNA and rRNA and has recently been investigated in eukaryotic mRNA1-3. However, the distribution, dynamics and functions of cytidine acetylation have yet to be fully elucidated. Here we report ac4C-seq, a chemical genomic method for the transcriptome-wide quantitative mapping of ac4C at single-nucleotide resolution. In human and yeast mRNAs, ac4C sites are not detected but can be induced-at a conserved sequence motif-via the ectopic overexpression of eukaryotic acetyltransferase complexes. By contrast, cross-evolutionary profiling revealed unprecedented levels of ac4C across hundreds of residues in rRNA, tRNA, non-coding RNA and mRNA from hyperthermophilic archaea. Ac4C is markedly induced in response to increases in temperature, and acetyltransferase-deficient archaeal strains exhibit temperature-dependent growth defects. Visualization of wild-type and acetyltransferase-deficient archaeal ribosomes by cryo-electron microscopy provided structural insights into the temperature-dependent distribution of ac4C and its potential thermoadaptive role. Our studies quantitatively define the ac4C landscape, providing a technical and conceptual foundation for elucidating the role of this modification in biology and disease4-6.


Asunto(s)
Acetilación , Citidina/análogos & derivados , Células Eucariotas/metabolismo , Evolución Molecular , ARN/química , ARN/metabolismo , Archaea/química , Archaea/citología , Archaea/genética , Archaea/crecimiento & desarrollo , Secuencia Conservada , Microscopía por Crioelectrón , Citidina/metabolismo , Células Eucariotas/citología , Células HeLa , Humanos , Modelos Moleculares , Acetiltransferasas N-Terminal/metabolismo , ARN de Archaea/química , ARN de Archaea/genética , Proteínas de Unión al ARN/metabolismo , Ribosomas/genética , Ribosomas/metabolismo , Ribosomas/ultraestructura , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/genética , Análisis de Secuencia de ADN , Temperatura
13.
ACS Chem Biol ; 15(6): 1301-1305, 2020 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-32275390

RESUMEN

RNA modifications play important roles in RNA structures and regulation of gene expression and translation. We report the first RNA modification on the phosphate, the RNA phosphorothioate (PS) modification, discovered in both prokaryotes and eukaryotes. The PS modification is also first reported on nucleic acids of eukaryotes. The GpsG modification exists in the Rp configuration and was quantified with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). By knocking out the DndA gene in E. coli, we show the Dnd clusters that regulate DNA PS modification may also play roles in RNA PS modification. We also show that the GpsG modification locates on rRNA in E. coli, L. lactis, and HeLa cells, and it is not detected in rRNA-depleted total RNAs from these cells.


Asunto(s)
Oligonucleótidos Fosforotioatos/análisis , ARN/química , Cromatografía Liquida , Escherichia coli/química , Células HeLa , Humanos , Procesamiento Postranscripcional del ARN , ARN Bacteriano/química , Espectrometría de Masas en Tándem
14.
Brain Behav Immun Health ; 4: 100069, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34589851

RESUMEN

Female and male mice of the BTBR T + Itpr3 tf /J (BTBR) strain have behaviors that resemble autism spectrum disorder. In comparison to C57BL/6 (B6) mice, BTBR mice have elevated humoral immunity, in that they have naturally high serum IgG levels and generate high levels of IgG antibodies, including autoantibodies to brain antigens. This study focused on the specificities of autoantibodies and the immune cells and their transcription factors that might be responsible for the autoantibodies. BTBR IgG autoantibodies bind to neurons better than microglia and with highest titer to nuclear antigens. Two of the antigens identified were alpha-enolase (ENO1) and dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex, mitochondrial (DLST). Surprisingly based on IgG levels, the blood and spleens of BTBR mice have more CD4+ and CD8+ T cells, but fewer B cells than B6 mice. The high levels of autoantibodies in BTBR relates to their splenic T follicular helper (Tfh) cell levels, which likely are responsible for the higher number of plasma cells in BTBR mice than B6 mice. BTBR mice have increased gene expression of interleukin-21 receptor (I l -21 r) and Paired Box 5 (Pax5), which are known to aid B cell differentiation to plasma cells, and an increased Lysine Demethylase 6B (Kdm6b)/DNA Methyltransferase 1 (Dnmt1) ratio, which increases gene expression. Identification of gene expression and immune activities of BTBR mice may aid understanding of mechanisms associated with autism since neuroimmune network interactions have been posited and induction of autoantibodies may drive the neuroinflammation associated with autism.

15.
Cell Chem Biol ; 27(3): 322-333.e5, 2020 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-31836350

RESUMEN

Acyl-coenzyme A (CoA)/protein interactions are essential for life. Despite this importance, their global scope and selectivity remains undefined. Here, we describe CATNIP (CoA/AcetylTraNsferase Interaction Profiling), a chemoproteomic platform for the high-throughput analysis of acyl-CoA/protein interactions in endogenous proteomes. First, we apply CATNIP to identify acetyl-CoA-binding proteins through unbiased clustering of competitive dose-response data. Next, we use this method to profile the selectivity of acyl-CoA/protein interactions, leading to the identification of specific acyl-CoA engagement signatures. Finally, we apply systems-level analyses to assess the features of protein networks that may interact with acyl-CoAs, and use a strategy for high-confidence proteomic annotation of acetyl-CoA-binding proteins to identify a site of non-enzymatic acylation in the NAT10 acetyltransferase domain that is likely driven by acyl-CoA binding. Overall, our studies illustrate how chemoproteomics and systems biology can be integrated to understand the roles of acyl-CoA metabolism in biology and disease.


Asunto(s)
Acilcoenzima A/química , Mapas de Interacción de Proteínas , Proteínas/química , Proteómica , Acilcoenzima A/metabolismo , Humanos , Proteínas/metabolismo
16.
EMBO J ; 38(23): e101323, 2019 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-31556460

RESUMEN

Estrogen receptor alpha (ERα) activity is associated with increased cancer cell proliferation. Studies aiming to understand the impact of ERα on cancer-associated phenotypes have largely been limited to its transcriptional activity. Herein, we demonstrate that ERα coordinates its transcriptional output with selective modulation of mRNA translation. Importantly, translational perturbations caused by depletion of ERα largely manifest as "translational offsetting" of the transcriptome, whereby amounts of translated mRNAs and corresponding protein levels are maintained constant despite changes in mRNA abundance. Transcripts whose levels, but not polysome association, are reduced following ERα depletion lack features which limit translation efficiency including structured 5'UTRs and miRNA target sites. In contrast, mRNAs induced upon ERα depletion whose polysome association remains unaltered are enriched in codons requiring U34-modified tRNAs for efficient decoding. Consistently, ERα regulates levels of U34-modifying enzymes and thereby controls levels of U34-modified tRNAs. These findings unravel a hitherto unprecedented mechanism of ERα-dependent orchestration of transcriptional and translational programs that may be a pervasive mechanism of proteome maintenance in hormone-dependent cancers.


Asunto(s)
Neoplasias de la Mama/genética , Receptor alfa de Estrógeno/genética , Regulación Neoplásica de la Expresión Génica , Polirribosomas/genética , Biosíntesis de Proteínas , ARN Mensajero/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Proliferación Celular , Receptor alfa de Estrógeno/metabolismo , Femenino , Humanos , Células MCF-7 , Polirribosomas/metabolismo , ARN Mensajero/metabolismo , Transducción de Señal , Activación Transcripcional
17.
ACS Chem Biol ; 14(7): 1403-1409, 2019 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-31243956

RESUMEN

Post-transcriptional modifications to messenger RNAs (mRNAs) have the potential to alter the biological function of this important class of biomolecules. The study of mRNA modifications is a rapidly emerging field, and the full complement of chemical modifications in mRNAs is not yet established. We sought to identify and quantify the modifications present in yeast mRNAs using an ultra-high performance liquid chromatography tandem mass spectrometry method to detect 40 nucleoside variations in parallel. We observe six modified nucleosides with high confidence in highly purified mRNA samples (N7-methylguanosine, N6-methyladenosine, 2'-O-methylguanosine, 2'-O-methylcytidine, N4-acetylcytidine, and 5-formylcytidine) and identify the yeast protein responsible for N4-acetylcytidine incorporation in mRNAs (Rra1). In addition, we find that mRNA modification levels change in response to heat shock, glucose starvation, and/or oxidative stress. This work expands the repertoire of potential chemical modifications in mRNAs and highlights the value of integrating mass spectrometry tools in the mRNA modification discovery and characterization pipeline.


Asunto(s)
Nucleósidos/análisis , ARN de Hongos/metabolismo , ARN Mensajero/metabolismo , Saccharomyces cerevisiae/metabolismo , Adenosina/análogos & derivados , Adenosina/análisis , Adenosina/metabolismo , Citidina/análogos & derivados , Citidina/análisis , Citidina/metabolismo , Glucosa/metabolismo , Guanosina/análogos & derivados , Guanosina/análisis , Guanosina/metabolismo , Respuesta al Choque Térmico , Nucleósidos/metabolismo , Estrés Oxidativo , ARN de Hongos/química , ARN Mensajero/química , Saccharomyces cerevisiae/química
18.
Sci Rep ; 9(1): 9006, 2019 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-31227723

RESUMEN

The anti-angiogenic agent, diamino propane tetraiodothyroacetic acid (DAT), is a thyro-integrin (integrin αvß3) antagonist anticancer agent that works via genetic and nongenetic actions. Tetraiodothyroacetic acid (tetrac) and DAT as thyroid hormone derivatives influence gene expression after they transport across cellular membranes. To restrict the action of DAT to the integrin αvß3 receptors on the cell surface, we used DAT-conjugated PLGA nanoparticles (NDAT) in an active targeting mode to bind to these receptors. Preparation and characterization of NDAT is described, and both in vitro and in vivo experiments were done to compare DAT to NDAT. Intracellular uptake and distribution of DAT and NDAT in U87 glioblastoma cells were evaluated using confocal microscopy and showed that DAT reached the nucleus, but NDAT was restricted from the nucleus. Pharmacokinetic studies using LC-MS/MS analysis in male C57BL/6 mice showed that administration of NDAT improved the area under the drug concentration curve AUC(0-48 h) by 4-fold at a dose of 3 mg/kg when compared with DAT, and Cmax of NDAT (4363 ng/mL) was 8-fold greater than that of DAT (548 ng/mL). Biodistribution studies in the mice showed that the concentrations of NDAT were higher than DAT/Cremophor EL micelles in heart, lung, liver, spleen, and kidney. In another mouse model using female NCr nude homozygous mice with U87 xenografts, tumor growth was significantly decreased at doses of 1 and 3 mg/kg of NDAT. In the chick chorioallantoic membrane (CAM) assay used to measure angiogenesis, DAT (500 ng/CAM) resulted in 48% inhibition of angiogenesis levels. In comparison, NDAT at low dose (50 ng/CAM) showed 45% inhibition of angiogenesis levels. Our investigation of NDAT bridges the study of polymeric nanoparticles and anti-angiogenic agents and offers new insight for the rational design of anti-angiogenic agents.


Asunto(s)
Materiales Biocompatibles/química , Nanopartículas/química , Polímeros/química , Propano/química , Tiroxina/análogos & derivados , Animales , Materiales Biocompatibles/farmacocinética , Materiales Biocompatibles/farmacología , Línea Celular Tumoral , Pollos , Membrana Corioalantoides/irrigación sanguínea , Membrana Corioalantoides/efectos de los fármacos , Membrana Corioalantoides/metabolismo , Femenino , Glioblastoma/irrigación sanguínea , Glioblastoma/tratamiento farmacológico , Glioblastoma/metabolismo , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Desnudos , Neovascularización Patológica/prevención & control , Tiroxina/química , Distribución Tisular , Ensayos Antitumor por Modelo de Xenoinjerto/métodos
19.
Org Lett ; 21(10): 3828-3833, 2019 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-31058515

RESUMEN

A chemoselective primary amine modification strategy that enables the three-component, one-pot bioconjugation is described. The specifically designed, mercaptobenzaldehyde-based bifunctional linker achieves highly selective and robust amine labeling under biocompatible conditions. This linker demonstrates wide functional group tolerance and is simple to prepare, which allowed facile payload incorporation. Finally, our studies have shown that the introduction of linker does not impair the function of modified protein such as insulin.


Asunto(s)
Aminas/química , Benzaldehídos/química , Procesamiento Proteico-Postraduccional/genética , Compuestos de Sulfhidrilo/química , Estructura Molecular
20.
Biosci Rep ; 39(2)2019 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-30737304

RESUMEN

Nephrolithiasis is one of the world's major public health burdens with a high incidence and a risk of persistent renal dysfunction. Fu-Fang-Jin-Qian-Chao granules (FFJQC), a traditional Chinese herb formula, is commonly used in treatment of nephrolithiasis. However, the therapeutic mechanism of FFJQC on kidney stone has still been a mystery. The objective of the present study is to explore the therapeutic mechanism of FFJQC on kidney injury and identify unique metabolomics patterns using a mouse model of kidney stone induced by a calcium oxalate (CaOx) deposition. Von Kossa staining and immuno-histopathological staining of osteopontin (OPN), cluster of differentiation 44 (CD44) and calbindin-D28k were conducted on renal sections. Biochemical analysis was performed on serum, urine, and kidney tissues. A metabolomics approach based on ultra-HPLC coupled with quadrupole-TOF-MS (UHPLC-Q-TOF/MS) was used for serum metabolic profiling. The immunohistopathological and biochemical analysis showed the therapeutic benefits of FFJQC. The expression levels of OPN and CD44 were decreased while calbindin-D28k increased after the CaOx injured mice were treated with FFJQC. In addition, total of 81 serum metabolites were identified to be associated with protective effects of FFJQC on CaOx crystal injured mice. Most of these metabolites were involved in purine, amino acid, membrane lipid and energy metabolism. Potential metabolite biomarkers were found for CaOx crystal-induced renal damage. Potential metabolite biomarkers of CaOx crystal-induced renal damage were found. FFJQC shows therapeutic benefits on CaOx crystal injured mice via regulation of multiple metabolic pathways including amino acids, purine, pyrimidine, glycerolipid, arachidonic acid (AA), sphingolipid, glycerophospholipid, and fatty acid.


Asunto(s)
Medicamentos Herbarios Chinos/uso terapéutico , Cálculos Renales/tratamiento farmacológico , Riñón/efectos de los fármacos , Metaboloma/efectos de los fármacos , Sustancias Protectoras/uso terapéutico , Animales , Oxalato de Calcio/efectos adversos , Modelos Animales de Enfermedad , Riñón/metabolismo , Riñón/patología , Cálculos Renales/etiología , Cálculos Renales/metabolismo , Cálculos Renales/patología , Masculino , Metabolómica , Ratones Endogámicos C57BL
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