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1.
Chemistry ; 30(5): e202302916, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-37902438

RESUMO

Blood continually contributes to the maintenance of homeostasis of the body and contains information regarding the health state of an individual. However, current hematological analyses predominantly rely on a limited number of CD markers and morphological analysis. In this work, differentially sensitive fluorescent compounds based on TCF scaffolds are introduced that are designed for fluorescent phenotyping of blood. Depending on their structures, TCF compounds displayed varied responses to reactive oxygen species, biothiols, redox-related biomolecules, and hemoglobin, which are the primary influential factors within blood. Contrary to conventional CD marker-based analysis, this unbiased fluorescent phenotyping method produces diverse fingerprints of the health state. Precise discrimination of blood samples from 37 mice was demonstrated based on their developmental stages, ranging from 10 to 19 weeks of age. Additionally, this fluorescent phenotyping method enabled the differentiation between drugs with distinct targets, serving as a simple yet potent tool for pharmacological analysis to understand the mode of action of various drugs.


Assuntos
Envelhecimento , Corantes Fluorescentes , Camundongos , Animais , Corantes Fluorescentes/química , Espécies Reativas de Oxigênio/análise , Oxirredução , Células Sanguíneas/química
2.
PLoS Genet ; 19(5): e1010750, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37186613

RESUMO

Curli amyloid fibers are a major constituent of the extracellular biofilm matrix formed by bacteria of the Enterobacteriaceae family. Within Escherichia coli biofilms, curli gene expression is limited to a subpopulation of bacteria, leading to heterogeneity of extracellular matrix synthesis. Here we show that bimodal activation of curli gene expression also occurs in well-mixed planktonic cultures of E. coli, resulting in all-or-none stochastic differentiation into distinct subpopulations of curli-positive and curli-negative cells at the entry into the stationary phase of growth. Stochastic curli activation in individual E. coli cells could further be observed during continuous growth in a conditioned medium in a microfluidic device, which further revealed that the curli-positive state is only metastable. In agreement with previous reports, regulation of curli gene expression by the second messenger c-di-GMP via two pairs of diguanylate cyclase and phosphodiesterase enzymes, DgcE/PdeH and DgcM/PdeR, modulates the fraction of curli-positive cells. Unexpectedly, removal of this regulatory network does not abolish the bimodality of curli gene expression, although it affects dynamics of activation and increases heterogeneity of expression levels among individual cells. Moreover, the fraction of curli-positive cells within an E. coli population shows stronger dependence on growth conditions in the absence of regulation by DgcE/PdeH and DgcM/PdeR pairs. We thus conclude that, while not required for the emergence of bimodal curli gene expression in E. coli, this c-di-GMP regulatory network attenuates the frequency and dynamics of gene activation and increases its robustness to cellular heterogeneity and environmental variation.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/metabolismo , Ativação Transcricional , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , GMP Cíclico/genética , GMP Cíclico/metabolismo , Sistemas do Segundo Mensageiro , Biofilmes , Regulação Bacteriana da Expressão Gênica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
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