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1.
J Transl Med ; 22(1): 48, 2024 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-38216927

RESUMEN

BACKGROUND: Muscle-invasive bladder cancer (MIBC) is a highly aggressive disease with a poor prognosis. B cells are crucial factors in tumor suppression, and tertiary lymphoid structures (TLSs) facilitate immune cell recruitment to the tumor microenvironment (TME). However, the function and mechanisms of tumor-infiltrating B cells and TLSs in MIBC need to be explored further. METHODS: We performed single-cell RNA sequencing analysis of 11,612 B cells and 55,392 T cells from 12 bladder cancer patients and found naïve B cells, proliferating B cells, plasma cells, interferon-stimulated B cells and germinal center-associated B cells, and described the phenotype, gene enrichment, cell-cell communication, biological processes. We utilized immunohistochemistry (IHC) and immunofluorescence (IF) to describe TLSs morphology in MIBC. RESULTS: The interferon-stimulated B-cell subtype (B-ISG15) and germinal center-associated B-cell subtypes (B-LMO2, B-STMN1) were significantly enriched in MIBC. TLSs in MIBC exhibited a distinct follicular structure characterized by a central region of B cells resembling a germinal center surrounded by T cells. CellChat analysis showed that CXCL13 + T cells play a pivotal role in recruiting CXCR5 + B cells. Cell migration experiments demonstrated the chemoattraction of CXCL13 toward CXCR5 + B cells. Importantly, the infiltration of the interferon-stimulated B-cell subtype and the presence of TLSs correlated with a more favorable prognosis in MIBC. CONCLUSIONS: The study revealed the heterogeneity of B-cell subtypes in MIBC and suggests a pivotal role of TLSs in MIBC outcomes. Our study provides novel insights that contribute to the precision treatment of MIBC.


Asunto(s)
Estructuras Linfoides Terciarias , Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Linfocitos B , Pronóstico , Músculos/patología , Interferones , Microambiente Tumoral
2.
Metabolomics ; 20(3): 57, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773045

RESUMEN

BACKGROUND: Despite the clear clinical diagnostic criteria for necrozoospermia in andrology, the fundamental mechanisms underlying it remain elusive. This study aims to profile the lipid composition in seminal plasma systematically and to ascertain the potential of lipid biomarkers in the accurate diagnosis of necrozoospermia. It also evaluates the efficacy of a lipidomics-based random forest algorithm model in identifying necrozoospermia. METHODS: Seminal plasma samples were collected from patients diagnosed with necrozoospermia (n = 28) and normozoospermia (n = 28). Liquid chromatography-mass spectrometry (LC-MS) was used to perform lipidomic analysis and identify the underlying biomarkers. A lipid functional enrichment analysis was conducted using the LION lipid ontology database. The top 100 differentially significant lipids were subjected to lipid biomarker examination through random forest machine learning model. RESULTS: Lipidomic analysis identified 46 lipid classes comprising 1267 lipid metabolites in seminal plasma. The top five enriched lipid functions as follows: fatty acid (FA) with ≤ 18 carbons, FA with 16-18 carbons, monounsaturated FA, FA with 18 carbons, and FA with 16 carbons. The top 100 differentially significant lipids were subjected to machine learning analysis and identified 20 feature lipids. The random forest model identified lipids with an area under the curve > 0.8, including LPE(20:4) and TG(4:0_14:1_16:0). CONCLUSIONS: LPE(20:4) and TG(4:0_14:1_16:0), were identified as differential lipids for necrozoospermia. Seminal plasma lipidomic analysis could provide valuable biochemical information for the diagnosis of necrozoospermia, and its combination with conventional sperm analysis may improve the accuracy and reliability of the diagnosis.


Asunto(s)
Algoritmos , Lipidómica , Semen , Adulto , Humanos , Masculino , Biomarcadores/sangre , Infertilidad Masculina/diagnóstico , Infertilidad Masculina/metabolismo , Lipidómica/métodos , Lípidos/análisis , Lípidos/sangre , Aprendizaje Automático , Bosques Aleatorios , Semen/metabolismo , Semen/química , Cromatografía Líquida con Espectrometría de Masas
3.
World J Microbiol Biotechnol ; 39(12): 352, 2023 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-37864750

RESUMEN

Formate dehydrogenase (FDH) is a D-2-hydroxy acid dehydrogenase, which can reversibly reduce CO2 to formate and thus act as non-photosynthetic CO2 reductase. In order to increase catalytic efficiency of formate dehydrogenase for CO2 reduction, two mutants V328I/F285W and V354G/F285W were obtained of which reduction activity was about two times more than the parent CbFDHM2, and the formate production from CO2 catalyzed by mutants were 2.9 and 2.7-fold higher than that of the parent CbFDHM2. The mutants had greater potential in CO2 reduction. The optimal temperature for V328I/F285W and V354G/F285W was 55 °C, and they showed increasement of relative activity under 45 °C to 55 °C compared with parent. The optimal pH for the mutants was 9.0, and they showed excellent stability in pH 4.0-11.5. The kcat/Km values of mutants were 1.75 times higher than that of the parent. Then the molecular basis for its improvement of biochemical characteristics were preliminarily elucidated by computer-aided methods. All of these results further established a solid foundation for molecular modification of formate dehydrogenase and CO2 reduction.


Asunto(s)
Dióxido de Carbono , Formiato Deshidrogenasas , Dióxido de Carbono/metabolismo , Formiato Deshidrogenasas/genética , Formiato Deshidrogenasas/química , Formiato Deshidrogenasas/metabolismo , Catálisis , Formiatos/metabolismo
4.
J Exp Bot ; 73(5): 1370-1384, 2022 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-34849737

RESUMEN

Fruit shape is an important quality and yield trait in melon (Cucumis melo). Although some quantitative trait loci for fruit shape have been reported in in this species, the genes responsible and the underlying mechanisms remain poorly understood. Here, we identified and characterized a gene controlling fruit shape from two melon inbred lines, B8 with long-horn fruit and HP22 with flat-round fruit. Genetic analysis suggested that the shape was controlled by a single and incompletely dominant locus, which we designate as CmFSI8/CmOFP13. This gene was finely mapped to a 53.7-kb interval on chromosome 8 based on bulked-segregant analysis sequencing and map-based cloning strategies. CmFSI8/CmOFP13 encodes an OVATE family protein (OFP) and is orthologous to AtOFP1 and SlOFP20. The transcription level of CmFSI8/CmOFP13 in the ovary of HP22 was significantly higher than that in B8, and sequence analysis showed that a 12.5-kb genomic variation with a retrotransposon insertion identified in the promoter was responsible for elevating the expression, and this ultimately caused the differences in fruit shape. Ectopic overexpression of CmFSI8/CmOFP13 in Arabidopsis led to multiple phenotypic changes, including kidney-shaped leaves and shortened siliques. Taken together, our results demonstrate the involvement of an OFP in regulating fruit shape in melon, and our improved understanding of the molecular mechanisms will enable us to better manipulate fruit shape in breeding.


Asunto(s)
Cucumis melo , Cucurbitaceae , Mapeo Cromosómico , Cucumis melo/genética , Cucurbitaceae/genética , Frutas/genética , Genes de Plantas , Fitomejoramiento
5.
Bioorg Med Chem Lett ; 72: 128729, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-35413415

RESUMEN

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated encouraging clinical outcomes for patients with EGFR-mutated non-small cell lung cancer, a considerable number of patients will develop drug resistance and eventually undergo disease progression after taking EGFR-TKIs for a period of time. EGFRdel19/T790M/C797S and EGFRL858R/T790M/C797S are two most prevalent tertiary EGFR mutants identified in Osimertinib-resistant tumors and currently there is no therapy approved clinically targeting these mutants. In this study, we designed and synthesized a series of novel 4th generation EGFR inhibitors based on scaffold of Brigatinib. After extensive SAR studies, compound 23, the most promising candidate, exhibited strong biochemical potencies against EGFRdel19/T790M/C797S, EGFRL858R/T790M/C797S and other clinically relevant EGFR mutants while sparing wild type EGFR. In cellular assays, compound 23 potently inhibited proliferation of BaF3EGFR del19/T790M/C797S and PC-9EGFR del19/T790M/C797S. Moreover, compound 23 demonstrated good DMPK profile in mouse PK study.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Animales , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Resistencia a Antineoplásicos , Receptores ErbB , Neoplasias Pulmonares/patología , Ratones , Mutación , Compuestos Organofosforados , Inhibidores de Proteínas Quinasas/química , Pirimidinas
6.
Zhonghua Nan Ke Xue ; 28(5): 408-414, 2022 May.
Artículo en Zh | MEDLINE | ID: mdl-37477479

RESUMEN

OBJECTIVE: To investigate the value of single-sperm sequencing technology in preimplantation genetic testing. METHODS: Haplotypes were constructed by single-sperm isolation combined with single-sperm sequencing for a patient with autosomal dominant polycystic kidney disease (ADPKD) caused by de novo mutation of the PKD1 gene c.3815T>G. 50. Single-sperm samples were isolated by mechanical braking, whole-genome amplification was performed, and mutation loci and their 187 upstream and downstream single nucleotide polymorphisms (SNP) were designed. The amplified products were verified for determination of the chromosome haplotypes carrying or not carrying pathogenic mutations. The embryos carrying pathogenic mutations were identified in 7 embryonic trophectoderm cell biopsy samples by high-throughput sequencing after whole-genome amplification. Available blastocysts were selected for embryo transfer, and amniotic fluid samples were collected at 18 weeks of gestation to determine whether the fetuses carried pathogenic mutations. RESULTS: A total of 30 SNPs were identified by single-sperm sequencing, and haplotypes were successfully constructed. Preimplantation haplotype analysis indicated that 5 embryos carried pathogenic mutations and 2 did not. mid-gestation amniotic fluid genetic testing revealed no PKD1 gene c.3815T>G mutation in the fetuses. CONCLUSION: SNPs can be identified by single-sperm sequencing in males carrying de novo pathogenic mutation, and haplotypes can be constructed by linkage analysis for preimplantation genetic testing of embryos.


Asunto(s)
Riñón Poliquístico Autosómico Dominante , Diagnóstico Preimplantación , Embarazo , Femenino , Humanos , Masculino , Riñón Poliquístico Autosómico Dominante/genética , Semen , Pruebas Genéticas , Mutación , Secuenciación de Nucleótidos de Alto Rendimiento , Espermatozoides , Tecnología
7.
Angew Chem Int Ed Engl ; 60(50): 26105-26114, 2021 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-34590387

RESUMEN

The autophagic ubiquitin-like protein LC3 functions through interactions with LC3-interaction regions (LIRs) of other autophagy proteins, including autophagy receptors, which stands out as a promising protein-protein interaction (PPI) target for the intervention of autophagy. Post-translational modifications like acetylation of Lys49 on the LIR-interacting surface could disrupt the interaction, offering an opportunity to design covalent small molecules interfering with the interface. Through screening covalent compounds, we discovered a small molecule modulator of LC3A/B that covalently modifies LC3A/B protein at Lys49. Activity-based protein profiling (ABPP) based evaluations reveal that a derivative molecule DC-LC3in-D5 exhibits a potent covalent reactivity and selectivity to LC3A/B in HeLa cells. DC-LC3in-D5 compromises LC3B lipidation in vitro and in HeLa cells, leading to deficiency in the formation of autophagic structures and autophagic substrate degradation. DC-LC3in-D5 could serve as a powerful tool for autophagy research as well as for therapeutic interventions.


Asunto(s)
Autofagia/efectos de los fármacos , Proteínas Asociadas a Microtúbulos/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Células HeLa , Humanos , Modelos Moleculares , Estructura Molecular , Bibliotecas de Moléculas Pequeñas/química
8.
Anticancer Drugs ; 27(7): 669-78, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27139820

RESUMEN

Cabozantinib capsules (COMETRIQ) are approved for the treatment of patients with progressive metastatic medullary thyroid cancer. Cabozantinib tablets are investigational drug products considered to be potentially preferred pharmaceutical dosing forms. Two phase I open-label single-dose studies in healthy individuals were carried out to characterize the plasma pharmacokinetics of cabozantinib capsule and tablet formulations: a two-way crossover bioequivalence study (n=77) comparing the tablet formulation and the marketed capsule formulation at the approved 140 mg dose and a dose-proportionality study (n=21 per treatment arm) evaluating the 20, 40, and 60 mg tablet strengths. In the bioequivalence study, plasma exposure [area under the plasma concentration-time curve (AUC0-t and AUC0-inf)] values were similar (<10% difference) for both formulations and the 90% confidence intervals (CIs) around the ratio of geometric least-squares means (GLSM) were within the accepted bioequivalence limits of 80-125%. However, the GLSM for Cmax was 19% higher for the tablet formulation and the upper 90% CI for the ratio of GLSM (131.65%) was beyond the 80-125% range. Thus, the tablet and capsule formulations failed to fulfill the bioequivalence study acceptance criteria. In the dose-proportionality study, single doses of the 20, 40, and 60 mg cabozantinib tablet strengths showed dose-proportional increases where the 95% CIs for the slopes of the ln-transformed Cmax, AUC0-t, and AUC0-inf values versus ln-transformed cabozantinib dose included the value of 1. These findings indicate that cabozantinib plasma exposures increased proportionally with increasing cabozantinib dose over the 20-60 mg tablet strength dose range.


Asunto(s)
Anilidas/administración & dosificación , Anilidas/farmacocinética , Piridinas/administración & dosificación , Piridinas/farmacocinética , Adolescente , Adulto , Anilidas/efectos adversos , Anilidas/sangre , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Antineoplásicos/sangre , Antineoplásicos/farmacocinética , Cápsulas , Estudios Cruzados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Piridinas/efectos adversos , Piridinas/sangre , Comprimidos , Equivalencia Terapéutica , Adulto Joven
9.
Mol Genet Genomic Med ; 12(3): e2343, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38156946

RESUMEN

BACKGROUND: Meckel syndrome (MKS) is the most severe form of an autosomal recessive ciliopathy and is clinically characterized by occipital encephalocele, severely polycystic kidneys, and postaxial polydactyly (toes). The association of TXNDC15-related MKS has been reported. We report the case of a homozygous mutation in the TXNDC15 gene, causing MKS14 in the Chinese population. METHODS: The fetal skin tissue and parental peripheral blood were retained for whole-exome sequencing and Sanger sequencing, which investigated the potential pathogenic variants associated with MKS. RESULTS: The fetus was homozygous for a mutation in the TXNDC15 gene (NM_024715.3), specifically c.560delA (p.Asn187llefsTer4), and both parents were heterozygous for this mutation. CONCLUSION: Our study identified a new mutation that adds to the mutational landscape of MKS, which provide a basis for genetic counseling and the selection of reproductive options.


Asunto(s)
Trastornos de la Motilidad Ciliar , Enfermedades Renales Poliquísticas , Retinitis Pigmentosa , Humanos , Encefalocele/genética , Enfermedades Renales Poliquísticas/genética , Enfermedades Renales Poliquísticas/patología , Trastornos de la Motilidad Ciliar/genética , Trastornos de la Motilidad Ciliar/patología , Mutación
10.
Am J Transl Res ; 16(8): 4246-4255, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39262744

RESUMEN

Aldosterone, a hormone synthesized by the adrenal cortex, plays a crucial role in regulating sodium and potassium levels in the kidneys through interaction with the mineralocorticoid receptor (MR) in the distal tubules and collecting ducts. While aldosterone aids in maintaining fluid balance by promoting sodium reabsorption and potassium secretion, elevated levels can lead to inflammation, oxidative stress, and organ damage. Experimental evidence highlights aldosterone's involvement in renal inflammation, collagen deposition, and fibrosis, often exacerbating the effects of therapies like angiotensin-converting enzyme inhibitors (ACEIs) by increasing proteinuria and vascular damage. Conversely, mineralocorticoid receptor antagonists (MRAs) show promise in mitigating these harmful effects. This review integrates current knowledge on aldosterone and MRAs, emphasizing their roles in renal health from both clinical and experimental perspectives. Additionally, the novel drug finerenone has shown favorable renal and cardiovascular outcomes in patients with diabetes and chronic kidney disease (CKD), warranting exploration of its potential use in other disease populations in future research.

11.
J Cancer ; 15(17): 5672-5690, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39308672

RESUMEN

Objective: Investigating the interaction between Mast cells (MCs) and Mononuclear Phagocytes (MPs) in the tumor microenvironment (TME) of blader cancer (BCa) to uncover potential immunotherapeutic targets. Methods: Single-cell RNA sequencing (scRNA-Seq) was conducted on 12 BCa patients to identify distinct subgroups of MCs and MPs. Transcriptome data was analyzed to characterize the phenotype, gene enrichment, cell-cell communication, and biological processes. The expression levels of cytokines were assessed by enzyme-linked immunosorbent assay (ELISA), while the chemotactic effects of cytokines were evaluated through Transwell assay. Results: In muscle-invasive bladder cancer (MIBC), the proportion of interferon-stimulated MC subtype (Mast-ISG15) increased. Mast-IL13 subgroup and Mast-CCL2 subgroups were functionally enriched in interferon (IFN) and nuclear factor kappa-B (NF-κB) signaling pathways. The Mast-CCL2 subgroup overexpressed the CCL2 gene, which could chemoattract MPs through CCL2. In vitro experiments confirmed that under stimulation, activated MCs activated IFN and NF-κB signaling, increasing the secretion of CCL2 and IL-13, chemoattracted THP-1 monocyte. Conclusion: This study revealed the vital role of MCs in shaping the TME of BCa. And provides new insights for the precise treatment of BCa.

12.
Diabetes Metab Syndr Obes ; 16: 4215-4231, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38162802

RESUMEN

Background: Diabetic kidney disease (DKD) is a chronic renal disease which could eventually develop into renal failure. Though albuminuria and estimated glomerular filtration rate (eGFR) are helpful for the diagnosis of DKD, the lack of specific biomarkers reduces the efficiency of therapeutic interventions. Methods: Based on bulk-seq of 56 urine samples collected at different time points (including 11 acquired from DKD patients and 11 from healthy controls), in corporation of scRNA-seq data of urine samples and snRNA-seq data of renal punctures from DKD patients (retrieved from NCBI GEO Omnibus), urine-kidney specific genes were identified by Multiple Biological Information methods. Results: Forty urine-kidney specific genes/differentially expressed genes (DEGs) were identified to be highly related to kidney injury and proteinuria for the DKD patients. Most of these genes participate in regulating glucagon and apoptosis, among which, urinary PART1 (mainly derived from distal tubular cells) and PLA2R1 (podocyte cell surface marker) could be used together for the early diagnosis of DKD. Moreover, urinary PART1 was significantly associated with multiple clinical indicators, and remained stable over time in urine. Conclusion: Urinary PART1 and PLA2R1 could be shed lights on the discovery and development of non-invasive diagnostic method for DKD, especially in early stages.

13.
World J Clin Cases ; 10(34): 12761-12767, 2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36579083

RESUMEN

BACKGROUND: Acephalic spermatozoa syndrome (ASS) is an extremely rare form of severe teratozoospermia, where in most of the sperm either appear to lack heads or have disconnected or poorly connected heads and tails. CASE SUMMARY: We reported the case of a male patient with secondary infertility whose sperm showed typical ASS upon morphological analysis. Whole-exome sequencing was performed on the patient's peripheral blood, which revealed two heterozygous variants of the PMFBP1 gene: PMFBP1c.414+1G>T (p.?) and PMFBP1c.393del (p.C132Afs*3). CONCLUSION: It is speculated that the compound homozygous mutation of PMFBP1 may be the cause of ASS. We conducted a literature review in order to provide the basis for genetic counseling and clinical diagnosis of patients with ASS.

14.
Bioorg Med Chem Lett ; 21(12): 3578-82, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21602044

RESUMEN

Newly developed monofluoromethylation reaction provided access to various bioactive molecules with an interesting monofluoromethyl unit. An iridium-catalyzed asymmetric version was employed for large-scale methyl-monofluorination of widely used nonsteroidal anti-inflammatory drug ibuprofen (the active S isoform). The methyl-monofluorinated ibuprofen was found to selectively inhibit cyclooxygenase-1 over cyclooxygenase-2 and surprisingly, the compound, with almost equal pharmacokinetic profile, was shown to increase analgesic activity and diminish gastric damage in animal models comparing to the parent drug ibuprofen. Therefore, methyl-monofluorination could be a useful strategy for improving efficacy and safety profile of drugs from the 'profen' family.


Asunto(s)
Ciclooxigenasa 1 , Inhibidores de la Ciclooxigenasa/síntesis química , Inhibidores de la Ciclooxigenasa/farmacología , Flúor/química , Mucosa Gástrica/efectos de los fármacos , Ibuprofeno , Antiinflamatorios no Esteroideos/síntesis química , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/farmacología , Células Cultivadas , Ciclooxigenasa 1/metabolismo , Inhibidores de la Ciclooxigenasa/química , Humanos , Ibuprofeno/química , Ibuprofeno/farmacología , Concentración 50 Inhibidora , Metilación , Estructura Molecular
15.
J Comput Aided Mol Des ; 25(9): 873-83, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21904909

RESUMEN

The lymphoid tyrosine phosphatase (LYP), encoded by the PTPN22 gene, has recently been identified as a promising drug target for human autoimmunity diseases. Like the majority of protein-tyrosine phosphatases LYP can adopt two functionally distinct forms determined by the conformation of the WPD-loop. The WPD-loop plays an important role in the catalytic dephosphorylation by protein-tyrosine phosphatases. Here we investigate the binding modes of two chemotypes of small molecule LYP inhibitors with respect to both protein conformations using computational modeling. To evaluate binding in the active form, we built a LYP protein structure model of high quality. Our results suggest that the two different compound classes investigated, bind to different conformations of the LYP phosphatase domain. Binding to the closed form is facilitated by an interaction with Asp195 in the WPD-loop, presumably stabilizing the active conformation. The analysis presented here is relevant for the design of inhibitors that specifically target either the closed or the open conformation of LYP in order to achieve better selectivity over phosphatases with similar binding sites.


Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Proteína Tirosina Fosfatasa no Receptora Tipo 22/antagonistas & inhibidores , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Dominio Catalítico , Humanos , Modelos Moleculares , Unión Proteica , Conformación Proteica , Proteína Tirosina Fosfatasa no Receptora Tipo 22/química
16.
Nucleic Acids Res ; 37(8): e59, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19293274

RESUMEN

The full understanding of dynamics of cellular processes hinges on the development of efficient and non-invasive labels for intracellular RNA species. Light-up aptamers binding fluorogenic ligands show promise as specific labels for RNA species containing those aptamers. Herein, we took advantage of existing, non-light-up aptamers against small molecules and demonstrated a new class of light-up probes in vitro. We synthesized two conjugates of thiazole orange dye to small molecules (GMP and AMP) and characterized in vitro their interactions with corresponding RNA aptamers. The conjugates preserved specific binding to aptamers while showing several 100-fold increase in fluorescence of the dye (the 'light-up' property). In the presence of free small molecules, conjugates can be displaced from aptamers serving also as fluorescent sensors. Our in vitro results provide the proof-of-concept that the small-molecule conjugates with light-up properties can serve as a general approach to label RNA sequences containing aptamers.


Asunto(s)
Adenosina Monofosfato/análogos & derivados , Aptámeros de Nucleótidos/química , Colorantes Fluorescentes/química , Guanosina Monofosfato/análogos & derivados , Tiazoles/química , Adenosina Monofosfato/síntesis química , Adenosina Monofosfato/química , Guanosina Monofosfato/síntesis química , Guanosina Monofosfato/química , Nucleótidos/química , Espectrometría de Fluorescencia , Tiazoles/síntesis química
17.
ACS Nano ; 15(11): 18014-18022, 2021 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-34677047

RESUMEN

Molecular adsorption conformations and arrangement configurations on surfaces are important structural aspects of surface stereochemistry, but their roles in steering the structures of metal-organic networks (MONs) remain vague and unexplored. In this study, we constructed MONs by the coordination self-assembly of isocyanides on Cu(111) and Ag(111) surfaces and demonstrated that the MON structures can be steered by surface stereochemistry, including the adsorption conformations of the isocyanide molecules and the arrangement configurations of the coordination nodes and subunits. The coordination self-assembly of 1,4-phenylene diisocyanobenzene afforded a honeycomb MON consisting of 3-fold (isocyano)3-Cu motifs on a Cu(111) surface. In contrast, geometrically different chevron-shaped 1,3-phenylene diisocyanobenzene (m-DICB) failed to generate a MON, which is ascribable to its standing conformation on the Cu(111) surface. However, m-DICB was adsorbed in a flat conformation on a Ag(111) surface, which has a larger lattice constant than a Cu(111) surface, and smoothly underwent coordination self-assembly to form a MON consisting of (isocyano)3-Ag motifs. Interestingly, only C3-Ag nodes with heterotactic configurations could grow into larger subunits; those subunits with heterotactic configurations further grew into Sierpinski triangle fractals (up to fourth order), while subunits with homotactic configurations afforded a triangular MON.

18.
Front Bioeng Biotechnol ; 9: 655522, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33859982

RESUMEN

Leucine dehydrogenase (LDH) is a NAD+-dependent oxidoreductase, which can selectively catalyze α-keto acids to obtain α-amino acids and their derivatives. It plays a key role in the biosynthesis of L-tert-leucine (L-Tle). As a non-naturally chiral amino acid, L-Tle can be used as an animal feed additive, nutrition fortifier, which is a perspective and important building block in the pharmaceutical, cosmetic, and food additive industry. In this study, four hypothetical leucine dehydrogenases were discovered by using genome mining technology, using the highly active leucine dehydrogenase LsLeuDH as a probe. These four leucine dehydrogenases were expressed in Escherichia coli BL21(DE3), respectively, and purified to homogeneity and characterized. Compared with the other enzymes, the specific activity of PfLeuDH also shows stronger advantage. In addition, the highly selective biosynthesis of L-Tle from trimethylpyruvic acid (TMP) was successfully carried out by whole-cell catalysis using engineered E. coli cells as biocatalyst, which can efficiently coexpress leucine dehydrogenase and formate dehydrogenase. One hundred-millimolar TMP was catalyzed for 25 h, and the yield and space-time yield of L-Tle reached 87.38% (e.e. >99.99%) and 10.90 g L-1 day-1. In short, this research has initially achieved the biosynthesis of L-Tle, laying a solid foundation for the realization of low-cost and large-scale biosynthesis of L-Tle.

19.
Nicotine Tob Res ; 12(2): 105-16, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20026503

RESUMEN

INTRODUCTION: It has been reported that adult smokers (AS) may be considering smokeless tobacco products as an alternative to smoking. The objective of this study was to evaluate the change in exposure in AS using Marlboro snus (MSNUS) (a tobacco pouch product in test market in June 2007). METHODS: AS were randomized into the following groups--CS: subjects (n = 30) continue smoking their own brand; DU: subjects (n = 60) reduced their daily cigarette consumption by >or=50% and were allowed to use MSNUS; SN: subjects (n = 15) stopped smoking their cigarettes but were allowed to use MSNUS; NT: subjects (n = 15) were not allowed to use any tobacco products for the entire duration of the 8-day study. Biomarkers of smoke exposure (BOE) measured at baseline and postbaseline were 24-hr urinary excretion of metabolites of N-nitrosamines, nicotine (urine and plasma), aromatic amines, benzene, and polycyclic aromatic hydrocarbon; urine mutagenicity; and carboxyhemoglobin at various timepoints. RESULTS: Statistically significant (p < .05) reductions in all the urinary BOE were observed in the DU group compared with the CS group. After correcting for the residual effect, a proportionate reduction (approximately 50%) in most of the biomarkers was observed. Even larger reductions, similar to the NT group, were observed in the SN group. DISCUSSION: The proportionate reduction in exposure when reducing the number of cigarettes by 50% and using MSNUS, under the consumption patterns observed, suggest that the AS did not appear to alter their smoking behavior. The added exposure from MSNUS usage in this group was minimal. The AS sustained substantial reductions in exposure when using MSNUS exclusively.


Asunto(s)
Monitoreo del Ambiente/métodos , Exposición por Inhalación/análisis , Nicotina/orina , Humo/análisis , Fumar/orina , Tabaco sin Humo/análisis , Administración por Inhalación , Adulto , Biomarcadores/orina , Butadienos/orina , Monóxido de Carbono/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nitrosaminas/orina , Pirenos/análisis , Adulto Joven
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