Background: In standard weaning from mechanical ventilation, a successful spontaneous breathing test (SBT) consisting of 30 min 8 cmHO pressure-support ventilation (PSV8) without positive end-expiratory pressure (PEEP) is followed by extubation with continuous suctioning; however, these practices might promote derecruitment. Evidence supports the feasibility and safety of extubation without suctioning. Ultrasound can assess lung aeration and respiratory muscles.
View Article and Find Full Text PDFThe generation of knockins is fundamental to dissect biological systems. SEED/Harvest, a technology based on CRISPR-Cas9, offers a powerful approach for seamless genome editing in Drosophila. Here, we present a protocol to tag any gene in the Drosophila genome using SEED/Harvest technology.
View Article and Find Full Text PDFCRISPR-Cas greatly facilitated the integration of exogenous sequences into specific loci. However, knockin generation in multicellular animals remains challenging, partially due to the complexity of insertion screening. Here, we describe SEED/Harvest, a method to generate knockins in Drosophila, based on CRISPR-Cas and the single-strand annealing (SSA) repair pathway.
View Article and Find Full Text PDFA new cooperative photoredox catalytic system, [Ru(trpy)(bpy)(HO)][3,3'-Co(8,9,12-Cl-1,2-CBH)], , has been synthesized and fully characterized for the first time. In this system, the photoredox catalyst [3,3'-Co(8,9,12-Cl-1,2-CBH)], a metallacarborane, and the oxidation catalyst [Ru(trpy)(bpy)(HO)], are linked by non-covalent interactions. This compound, along with the one previously synthesized by us, [Ru(trpy)(bpy)(HO)][(3,3'-Co(1,2-CBH)], 4, are the only examples of cooperative molecular photocatalysts in which the catalyst and photosensitizer are not linked by covalent bonds.
View Article and Find Full Text PDFGlypicans (Glps) are a family of heparan sulphate proteoglycans that are attached to the outer plasma membrane leaflet of the producing cell by a glycosylphosphatidylinositol anchor. Glps are involved in the regulation of many signalling pathways, including those that regulate the activities of Wnts, Hedgehog (Hh), Fibroblast Growth Factors (FGFs), and Bone Morphogenetic Proteins (BMPs), among others. In the Hh-signalling pathway, Glps have been shown to be essential for ligand transport and the formation of Hh gradients over long distances, for the maintenance of Hh levels in the extracellular matrix, and for unimpaired ligand reception in distant recipient cells.
View Article and Find Full Text PDFDuring embryonic development, cell-cell communication is crucial to coordinate cell behavior, especially in the generation of differentiation patterns via morphogen gradients. Morphogens are signaling molecules secreted by a source of cells that elicit concentration-dependent responses in target cells. For several morphogens, cell-cell contact via filopodia-like-structures (cytonemes) has been proposed as a mechanism for their gradient formation.
View Article and Find Full Text PDFThe function of Hedgehog (Hh) as a morphogen results from its long-distance distribution from producing to neighboring receiving cells within the developing tissue. This signal distribution enables, for example, the formation of a concentration gradient eliciting distinct cellular responses that will give rise to spatial patterning. Hh is a lipid modified protein and its dispersion is better guaranteed through cytonemes, cell protrusions that allow direct cell membrane contact and signal transfer at a distance.
View Article and Find Full Text PDFThe conserved family of Hedgehog (Hh) signaling proteins plays a key role in cell-cell communication in development, tissue repair, and cancer progression, inducing distinct concentration-dependent responses in target cells located at short and long distances. One simple mechanism for long distance dispersal of the lipid modified Hh is the direct contact between cell membranes through filopodia-like structures known as cytonemes. Here we have analyzed in the interaction between the glypicans Dally and Dally-like protein, necessary for Hh signaling, and the adhesion molecules and Hh coreceptors Ihog and Boi.
View Article and Find Full Text PDFMorphogen gradients are crucial for the development of organisms. The biochemical properties of many morphogens prevent their extracellular free diffusion, indicating the need of an active mechanism for transport. The involvement of filopodial structures (cytonemes) has been proposed for morphogen signaling.
View Article and Find Full Text PDFAn original cooperative photoredox catalytic system, [Ru(trpy)(bpy)(HO)][3,3'-Co(1,2-CBH)] (; trpy = terpyridine and bpy = bipyridine), has been synthesized. In this system, the photoredox metallacarborane catalyst [3,3'-Co(1,2-CBH)] () and the oxidation catalyst [Ru(trpy)(bpy)(HO)] () are linked by noncovalent interactions and not through covalent bonds. The noncovalent interactions to a large degree persist even after water dissolution.
View Article and Find Full Text PDFExtracellular vesicles (EVs) mediate cell-to-cell crosstalk whose content can induce changes in acceptor cells and their microenvironment. MLP29 cells are mouse liver progenitor cells that release EVs loaded with signaling cues that could affect cell fate. In the current work, we incubated 3T3-L1 mouse fibroblasts with MLP29-derived EVs, and then analyzed changes by proteomics and transcriptomics.
View Article and Find Full Text PDFA successful homogeneous photoredox catalyst has been fruitfully heterogenized on magnetic nanoparticles (MNPs) coated with a silica layer, keeping intact its homogeneous catalytic properties but gaining others due to the easy magnetic separation and recyclability. The amine-terminated magnetic silica nanoparticles linked noncovalently to H[3,3'-Co(1,2-CBH)] (H[]), termed MSNPs-NH@H[], are highly stable and do not produce any leakage of the photoredox catalyst H[] in water. The magnetite MNPs were coated with SiO to provide colloidal stability and silanol groups to be tethered to amine-containing units.
View Article and Find Full Text PDFLipidated morphogens can spread within tissues to regulate cell fate during development or tissue repair. How these insoluble molecules reach distant target cells remains unclear. Reporting in Nature, McGough et al.
View Article and Find Full Text PDFHedgehog (Hh) signal molecules play a fundamental role in development, adult stem cell maintenance and cancer. Hh can signal at a distance, and we have proposed that its graded distribution across Drosophila epithelia is mediated by filopodia-like structures called cytonemes. Hh reception by Patched (Ptc) happens at discrete sites along presenting and receiving cytonemes, reminiscent of synaptic processes.
View Article and Find Full Text PDFMetallacarboranes with the shape of the Greek letter θ, such as [Co(C B H ) ] , were tested, for the first time, as efficient photoredox catalysts in the oxidation of aromatic and aliphatic alcohols in water. Their efficiency is linked to their high solubility in water, their high oxidizing power (Co ), and their absence of fluorescence on excitation, among others. In most of the studied examples, using a catalyst load of 0.
View Article and Find Full Text PDFSpecific neuropeptides regulate in arthropods the shedding of the old cuticle (ecdysis) followed by maturation of the new cuticle. In , the last ecdysis occurs at eclosion from the pupal case, with a post-eclosion behavioural sequence that leads to wing extension, cuticle stretching and tanning. These events are highly stereotyped and are controlled by a subset of crustacean cardioactive peptide (CCAP) neurons through the expression of the neuropeptide Bursicon (Burs).
View Article and Find Full Text PDFDuring development, specialized cells produce signals that distribute among receiving cells to induce a variety of cellular behaviors and organize tissues. Recent studies have highlighted cytonemes, a type of specialized signaling filopodia that carry ligands and/or receptor complexes, as having a role in signal dispersion. In this Primer, we discuss how the dynamic regulation of cytonemes facilitates signal transfer in complex environments.
View Article and Find Full Text PDFSignalling from cell-to-cell is fundamental for determining differentiation and patterning. This communication can occur between adjacent and distant cells. Extracellular vesicles (EVs) are membrane-based structures thought to facilitate the long-distance movement of signalling molecules.
View Article and Find Full Text PDFMorphogens regulate tissue patterning through their distribution in concentration gradients. Emerging research establishes a role for specialized signalling filopodia, or cytonemes, in morphogen dispersion and signalling. Previously we demonstrated that Hedgehog (Hh) morphogen is transported via vesicles along cytonemes emanating from signal-producing cells to form a gradient in epithelia.
View Article and Find Full Text PDFIntercellular communication is a fundamental process for correct tissue development. The mechanism of this process involves, among other things, the production and secretion of signaling molecules by specialized cell types and the capability of these signals to reach the target cells in order to trigger specific responses. Hedgehog (Hh) is one of the best-studied signaling pathways because of its importance during morphogenesis in many organisms.
View Article and Find Full Text PDFHedgehog (Hh) molecules act as morphogens directing cell fate during development by activating various target genes in a concentration dependent manner. Hitherto, modeling morphogen gradient formation in multicellular systems has employed linear diffusion, which is very far from physical reality and needs to be replaced by a deeper understanding of nonlinearities. We have developed a novel mathematical approach by applying flux-limited spreading (FLS) to Hh morphogenetic actions.
View Article and Find Full Text PDFThe Hedgehog (Hh) signaling pathway is a regulator of patterning, cell migration and axon guidance during development as well as of homeostatic events in adult organs. It is highly conserved from Drosophila to humans. In many contexts during development, Hh appears to function as a morphogen; it spreads from producing cells to trigger concentration dependent responses in target cells, leading to their specification.
View Article and Find Full Text PDFIn Drosophila, decapentaplegic, which codes for a secreted signaling molecule, is activated by the Hedgehog signaling pathway at the anteroposterior compartment border of the two dorsal primordia; the wing and the haltere imaginal discs. In the wing disc, Decapentaplegic and Hedgehog signaling targets are implicated in cell proliferation and cell survival. However, most of their known targets in the wing disc are not expressed in the haltere disc due to their repression by the Hox gene Ultrabithorax.
View Article and Find Full Text PDFThe Hedgehog signalling pathway is crucial for development, adult stem cell maintenance, cell migration and axon guidance in a wide range of organisms. During development, the Hh morphogen directs tissue patterning according to a concentration gradient. Lipid modifications on Hh are needed to achieve graded distribution, leading to debate about how Hh is transported to target cells despite being membrane-tethered.
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