In the version of this Article originally published, in ref. 34 the first author's name was spelled incorrectly. The correct reference is: Rodón, L.
View Article and Find Full Text PDFIn the version of this Article originally published, the competing interests statement was missing. The authors declare no competing interests; this statement has now been added in all online versions of the Article.
View Article and Find Full Text PDFStress is integral to tumour evolution, and cancer cell survival depends on stress management. We found that cancer-associated stress chronically activates the bioenergetic sensor AMP kinase (AMPK) and, to survive, tumour cells hijack an AMPK-regulated stress response pathway conserved in normal cells. Analysis of The Cancer Genome Atlas data revealed that AMPK isoforms are highly expressed in the lethal human cancer glioblastoma (GBM).
View Article and Find Full Text PDFThe RASopathy neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant genetic disorders. In NF1 patients, neurological issues may result from damaged myelin, and mice with a neurofibromin gene (Nf1) mutation show white matter (WM) defects including myelin decompaction. Using mouse genetics, we find that altered Nf1 gene-dose in mature oligodendrocytes results in progressive myelin defects and behavioral abnormalities mediated by aberrant Notch activation.
View Article and Find Full Text PDFUnlabelled: Spinal reflex circuit development requires the precise regulation of axon trajectories, synaptic specificity, and synapse formation. Of these three crucial steps, the molecular mechanisms underlying synapse formation between group Ia proprioceptive sensory neurons and motor neurons is the least understood. Here, we show that the Rho GTPase Cdc42 controls synapse formation in monosynaptic sensory-motor connections in presynaptic, but not postsynaptic, neurons.
View Article and Find Full Text PDFA prerequisite to myelination of peripheral axons by Schwann cells (SCs) is SC differentiation, and recent evidence indicates that reprogramming from a glycolytic to oxidative metabolism occurs during cellular differentiation. Whether this reprogramming is essential for SC differentiation, and the genes that regulate this critical metabolic transition are unknown. Here we show that the tumour suppressor Lkb1 is essential for this metabolic transition and myelination of peripheral axons.
View Article and Find Full Text PDFTransmission electron microscopy (TEM) provides ultra-structural details of cells at the sub-organelle level. However, details of the cellular ultrastructure, and the cellular organization and content of various organelles in rare populations, particularly in the suspension, like hematopoietic stem cells (HSCs) remained elusive. This is mainly due to the requirement of millions of cells for TEM studies.
View Article and Find Full Text PDFPatients with neurofibromatosis type 1 (NF1) and Costello syndrome Rasopathy have behavioral deficits. In NF1 patients, these may correlate with white matter enlargement and aberrant myelin. To model these features, we induced Nf1 loss or HRas hyperactivation in mouse oligodendrocytes.
View Article and Find Full Text PDFPlexiform neurofibromas are peripheral nerve sheath tumors initiated by biallelic mutation of the NF1 tumor suppressor gene in the Schwann cell lineage. To understand whether neurofibroma formation is possible after birth, we induced Nf1 loss of function with an inducible proteolipid protein Cre allele. Perinatal loss of Nf1 resulted in the development of small plexiform neurofibromas late in life, whereas loss in adulthood caused large plexiform neurofibromas and morbidity beginning 4 months after onset of Nf1 loss.
View Article and Find Full Text PDFIn certain regions of the body, transition zones exist where stratified squamous epithelia directly abut against other types of epithelia. Certain transition zones are especially prone to tumorigenesis an example being the anorectal junction, although the reason for this is not known. One possibility is that the abrupt transition of the simple columnar epithelium of the colon to the stratified squamous epithelium of the proximal portion of the anal canal may contain a unique stem cell niche.
View Article and Find Full Text PDFHistoplasma capsulatum is a fungal pathogen that requires the induction of cell-mediated immunity (CMI) for host survival. We have demonstrated that human dendritic cells (DC) phagocytose H. capsulatum yeasts and, unlike human macrophages (Mø) that are permissive for intracellular growth, DC killed and degraded the fungus.
View Article and Find Full Text PDFMagmas, is a 13-kDa mitochondrial protein which is ubiquitously expressed in eukaryotic cells. It was identified as a granulocyte-macrophage-colony stimulating factor (GM-CSF) inducible gene in hematopoietic cells and has a key role in the transport of mitochondrial proteins in yeast. Because GM-CSF receptor levels are elevated in prostate cancer, Magmas expression was examined in normal and neoplastic tissue.
View Article and Find Full Text PDFApoptosis was induced rapidly in HeLa cells after exposure to bacterial Shiga toxin (Stx1 and Stx2; 10 ng/ml). Approximately 60% of HeLa cells became apoptotic within 4 h as detected by DNA fragmentation, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, and electron microscopy. Stx1-induced apoptosis required enzymatic activity of the Stx1A subunit, and apoptosis was not induced by the Stx2B subunit alone or by the anti-globotriaosylceramide antibody.
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