Publications by authors named "Ambra Villani"

Article Synopsis
  • Microglia are special brain cells that help with brain health and development by cleaning up dead neurons.
  • In a disease called Niemann-Pick type C, microglia change shape and become less effective at their job when a protein called NPC1 is missing.
  • Researchers used zebrafish to show that without NPC1, microglia gather too much cholesterol and their “cleaning spots” get bigger, making them more sensitive to dying brain cells, which could help in understanding the disease better.
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During development, inflammation or tissue injury, macrophages may successively engulf and process multiple apoptotic corpses via efferocytosis to achieve tissue homeostasis. How macrophages may rapidly adapt their transcription to achieve continuous corpse uptake is incompletely understood. Transcriptional pause/release is an evolutionarily conserved mechanism, in which RNA polymerase (Pol) II initiates transcription for 20-60 nucleotides, is paused for minutes to hours and is then released to make full-length mRNA.

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During brain development, many newborn neurons undergo apoptosis and are engulfed by microglia, the tissue-resident phagocytes of the brain, in a process known as efferocytosis. A hallmark of microglia is their highly branched morphology characterized by the presence of numerous dynamic extensions that these cells use for scanning the brain parenchyma and engulfing unwanted material. The mechanisms driving branch formation and apoptotic cell engulfment in microglia are unclear.

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Cerebral palsy (CP) is still the most common cause of disability developing in infancy. How such a complex disorder affects adult life raises important questions on the critical issues to consider and the most appropriate care pathway right from early childhood. We conducted a multicenter study on a sample of 109 individuals with CP followed up from infancy and recalled for an assessment at ages ranging between 18 and 50 years (mean age 26 years).

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Phagocytic immune cells such as microglia can engulf and process pathogens and dying cells with high efficiency while still maintaining their dynamic behavior and morphology. Effective intracellular processing of ingested cells is likely to be crucial for microglial function, but the underlying cellular mechanisms are poorly understood. Using both living fish embryos and mammalian macrophages, we show that processing depends on the shrinkage and packaging of phagosomes into a unique cellular compartment, the gastrosome, with distinct molecular and ultra-structural characteristics.

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Many aspects of brain development, function, and repair depend on the interaction of neurons with brain immune cells, the microglia. By combining CLEM and SPIM microscopy, a recent study has challenged the current view that microglia can "eat" entire synapses, highlighting the incredible complexity of neuronal-microglial interactions in vivo.

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Background & Aims: Genetic defects in polycystin-1 or -2 (PC1 or PC2) cause polycystic liver disease associated with autosomal dominant polycystic kidney disease (PLD-ADPKD). Progressive cyst growth is sustained by a cAMP-dependent Ras/ERK/HIFα pathway, leading to increased vascular endothelial growth factor A (VEGF-A) signaling. In PC2-defective cholangiocytes, cAMP production in response to [Ca] depletion is increased, while store-operated Ca entry (SOCE), intracellular and endoplasmic reticulum [Ca] levels are reduced.

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Unlabelled: In the liver, the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) regulates bile secretion and other functions at the apical membrane of biliary epithelial cells (i.e., cholangiocytes).

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Unlabelled: Polycystin-2 (PC2 or TRPPC2), a member of the transient receptor potential channel family, is a nonselective calcium channel. Mutations in PC2 are associated with polycystic liver diseases. PC2-defective cholangiocytes show increased production of cyclic adenosine monophosphate, protein kinase A-dependent activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway, hypoxia-inducible factor 1α (HIF-1α)-mediated vascular endothelial growth factor (VEGF) production, and stimulation of cyst growth and progression.

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Unlabelled: Cystic fibrosis-associated liver disease is a chronic cholangiopathy that negatively affects the quality of life of cystic fibrosis patients. In addition to reducing biliary chloride and bicarbonate secretion, up-regulation of toll-like receptor 4/nuclear factor kappa light-chain-enhancer of activated B cells (NF-κB)-dependent immune mechanisms plays a major role in the pathogenesis of cystic fibrosis-associated liver disease and may represent a therapeutic target. Nuclear receptors are transcription factors that regulate several intracellular functions.

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