Biochem Pharmacol
November 2024
Alamandine (ALA) exerts protective effects similar to angiotensin (Ang) (1-7) through Mas-related G protein-coupled receptor type D receptor (MrgDR) activation, distinct from Mas receptor (MasR). ALA induces anti-inflammatory effects in mice but its impact in human macrophages remains unclear. We aimed to investigate the anti-inflammatory effects of ALA in human macrophages.
View Article and Find Full Text PDFMotivation: Chemical reaction networks (CRNs) play a pivotal role in diverse fields such as systems biology, biochemistry, chemical engineering, and epidemiology. High-level definitions of CRNs enables to use various simulation approaches, including deterministic and stochastic methods, from the same model. However, existing Python tools for simulation of CRN typically wrap external C/C++ libraries for model definition, translation into equations and/or numerically solving them, limiting their extensibility and integration with the broader Python ecosystem.
View Article and Find Full Text PDFBackground: In tissues and organisms, the coordination of neighboring cells is essential to maintain their properties and functions. Therefore, knowing which cells are adjacent is crucial to understand biological processes that involve physical interactions among them, e.g.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
April 2023
Background estimation is the first step in quantitative analysis of images. It has an impact on all subsequent analyses, in particular for segmentation and calculation of ratiometric quantities. Most methods recover only a single value such as the median or yield a biased estimation in non-trivial cases.
View Article and Find Full Text PDFApoptosis is a mechanism of programmed cell death in which cells engage in a controlled demolition and prepare to be digested without damaging their environment. In normal conditions, apoptosis is repressed until it is irreversibly induced by an appropriate signal. In adult organisms, apoptosis is a natural way to dispose of damaged cells and its disruption or excess is associated with cancer and autoimmune diseases.
View Article and Find Full Text PDFImaging molecular patterns in cells by fluorescence micro- or nanoscopy has the potential to relate collective molecular behavior to cellular function. However, spatial and spectroscopic resolution is fundamentally limited by motional blur caused by finite photon fluxes and photobleaching. At physiological temperatures, photochemical reactivity does not only limit imaging at multiple scales but is also toxic to biochemical reactions that maintain cellular organization.
View Article and Find Full Text PDFSmaug is a conserved translational regulator that binds numerous mRNAs, including nuclear transcripts that encode mitochondrial enzymes. Smaug orthologs form cytosolic membrane-less organelles (MLOs) in several organisms and cell types. We have performed single-molecule fluorescence in situ hybridization (FISH) assays that revealed that SDHB and UQCRC1 mRNAs associate with Smaug1 bodies in U2OS cells.
View Article and Find Full Text PDFIn this work we use lanthanide based NaYF:Er, Ybupconversion nanoparticles (UCNP) to detect ppb-level sensitibity of a xanthene dye, Rhodamine B (RB) dye, under NIR excitation. A static energy transfer was observed between the luminescent UCNP energy donors and RB acceptor in aqueous solution for three different sizes of UCNP. No specific covalent functionalization of the UCNPs was performed providing a direct method of detection, particularly promising in natural systems where the interfering fluorescence background is a detrimental limitation to the performance of the detection method.
View Article and Find Full Text PDFUnderstanding signal propagation across biological networks requires to simultaneously monitor the dynamics of several nodes to uncover correlations masked by inherent intercellular variability. To monitor the enzymatic activity of more than two components over short time scales has proven challenging. Exploiting the narrow spectral width of homo-FRET-based biosensors, up to three activities can be imaged through fluorescence polarization anisotropy microscopy.
View Article and Find Full Text PDFGastrulation is a key event in animal embryogenesis during which germ layer precursors are rearranged and the embryonic axes are established. Cell polarization is essential during gastrulation, driving asymmetric cell division, cell movements, and cell shape changes. The furry (fry) gene encodes an evolutionarily conserved protein with a wide variety of cellular functions, including cell polarization and morphogenesis in invertebrates.
View Article and Find Full Text PDFCell migration has been a subject of study in a broad variety of biological systems, from morphogenetic events during development to cancer progression. In this work, we describe single-cell movement in a modular framework from which we simulate the collective behavior of glioblastoma cells, the most prevalent and malignant primary brain tumor. We used the U87 cell line, which can be grown as a monolayer or spatially closely packed and organized in 3D structures called spheroids.
View Article and Find Full Text PDFThe development of light-sheet fluorescence microscopy has been a revolution for developmental biology as it allows long-term imaging during embryonic development. An important reason behind the quick adoption has been the availability of open hardware alternatives. In this work, we present a robust and compact version of a light-sheet fluorescence microscope that is easy to assemble and requires little to no maintenance.
View Article and Find Full Text PDFBiological systems are spatially organized. This microscopic heterogeneity has been shown to produce emergent complex behaviors such as bistability. Even though the connection between spatiality and dynamic response is essential to understand biological output, its robustness and extent has not been sufficiently explored.
View Article and Find Full Text PDFAge-related macular degeneration (AMD) is a multifactorial retinal disease characterized by a progressive loss of central vision. Retinal pigment epithelium (RPE) degeneration is a critical event in AMD. It has been associated to A2E accumulation, which sensitizes RPE to blue light photodamage.
View Article and Find Full Text PDFThe proto-oncogenic epidermal growth factor receptor (EGFR) is a tyrosine kinase whose sensitivity to growth factors and signal duration determines cellular behavior. We resolve how EGFR's response to epidermal growth factor (EGF) originates from dynamically established recursive interactions with spatially organized protein tyrosine phosphatases (PTPs). Reciprocal genetic PTP perturbations enabled identification of receptor-like PTPRG/J at the plasma membrane and ER-associated PTPN2 as the major EGFR dephosphorylating activities.
View Article and Find Full Text PDFThe synthesis and photophysical properties of a tailored Pt(II) complex are presented. The phosphorescence of its monomeric species in homogeneous solutions is quenched by interaction with the solvent and therefore absent even upon deoxygenation. However, aggregation-induced shielding from the environment and suppression of rotovibrational degrees of freedom trigger a phosphorescence turn-on that is not suppressed by molecular oxygen, despite possessing an excited-state lifetime ranging in the microsecond scale.
View Article and Find Full Text PDFFocal adhesions anchor contractile actin fibers with the extracellular matrix, sense the generated tension and respond to it by changing their morphology and composition. Here we ask how this mechanosensing is enabled at the protein-network level, given the modular assembly and multitasking of focal adhesions. To address this, we applied a sensitive 4-color live cell imaging approach, enabling monitoring patterns of molecular changes in single focal adhesions.
View Article and Find Full Text PDFThe MAS1 receptor (R) exerts protective effects in the brain, heart, vessels, and kidney. R trafficking plays a critical function in signal termination and propagation and in R resensitization. We examined MAS1R internalization and trafficking on agonist stimulation and the role of β-arrestin2 in the activation of ERK1/2 (extracellular signal-regulated kinase 1/2) and Akt after MAS1R stimulation.
View Article and Find Full Text PDFMethods Appl Fluoresc
June 2017
Förster resonant energy transfer measured by fluorescence lifetime imaging microscopy (FRET-FLIM) is the method of choice for monitoring the spatio-temporal dynamics of protein interactions in living cells. To obtain an accurate estimate of the molecular fraction of interacting proteins requires a large number of photons, which usually precludes the observation of a fast process, particularly with time correlated single photon counting (TCSPC) based FLIM. In this work, we propose a novel method named pawFLIM (phasor analysis via wavelets) that allows the denoising of FLIM datasets by adaptively and selectively adjusting the desired compromise between spatial and molecular resolution.
View Article and Find Full Text PDFBradykinin B2 receptor (B2R) and angiotensin-(1-7) Mas receptor (MasR)-mediated effects are physiologically interconnected. The molecular basis for such cross talk is unknown. It is hypothesized that the cross talk occurs at the receptor level.
View Article and Find Full Text PDFIntegrin adhesome proteins bind each other in alternative manners, forming within the cell diverse cell-matrix adhesion sites with distinct properties. An intriguing question is how such modular assembly of adhesion sites is achieved correctly solely by self-organization of their components. Here we address this question using high-throughput multiplexed imaging of eight proteins and two phosphorylation sites in a large number of single focal adhesions.
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