Search results for " stem"
showing 10 items of 2170 documents
Ulipristal acetate. A new emergency contraceptive. Ethical aspects of its use
2010
Nel 2006, Takahashi e Yamanaka hanno dimostrato, per la prima volta, che i fibroblasti di topo possono essere riprogrammati ad uno stato simile a quello di cellule staminali embrionali con l’introduzione di una combinazione di quattro fattori di trascrizione. Queste cellule sono state chiamate “cellule staminali pluripotenti indotte” o “cellule iPS”. A differenza delle cellule staminali embrionali, l’uso di cellule iPS non solleva questioni etiche. In questo articolo, si fa riferimento in particolare a: 1. esperimenti preclinici condotti fino ad oggi utilizzando cellule iPS, 2. la creazione di linee cellulari a partire da cellule iPS ottenute da cellule adulte di pazienti affetti da varie m…
Sodium channels enable fast electrical signaling and regulate phagocytosis in the retinal pigment epithelium
2019
Background Voltage-gated sodium (Nav) channels have traditionally been considered a trademark of excitable cells. However, recent studies have shown the presence of Nav channels in several non-excitable cells, such as astrocytes and macrophages, demonstrating that the roles of these channels are more diverse than was previously thought. Despite the earlier discoveries, the presence of Nav channel-mediated currents in the cells of retinal pigment epithelium (RPE) has been dismissed as a cell culture artifact. We challenge this notion by investigating the presence and possible role of Nav channels in RPE both ex vivo and in vitro. Results Our work demonstrates that several subtypes of Nav cha…
Uniform climate sensitivity in tree-ring stable isotopes across species and sites in a mid-latitude temperate forest.
2014
Tree-ring stable isotopes, providing insight into drought-induced eco-physiological mechanisms, are frequently used to reconstruct past changes in growing season temperature and precipitation. Their climatic response is, however, still not fully understood, particularly for data originating from non-extreme, mid-latitude environments with differing ecological conditions. Here, we assess the response of δ(13)C, δ(18)O and tree-ring width (TRW) from a temperate mountain forest in the Austrian pre-Alps to climate and specific drought events. Variations in stem growth and isotopic composition of Norway spruce, common beech and European larch from dry, medium and moist sites are compared with re…
Ultrastructural Studies on Development in Mature Seeds; Embryos ofEuonymus europaeaL. Dormant or Cultured at +25 °C
1989
Ultrastructural observations on naturally dispersed and dehydrated seeds of Euonymus europaea L. were performed. It was shown that during the culture of isolated embryos at 25 °C for 7 d the maturation of protein bodies continued; the initial juvenile form (single protein body per cell with dispersed contents) was developing into a more advanced form (single body split to form several sub-units with condensed contents). Parallel biochemical determinations pointed to an increase in insoluble protein levels. There were no changes in other storage organelles, lipid bodies, either in the fine structure or in the level of triacylglycerols. Deterioration of cellular membranes (in mitochondria, pr…
<i>In vitro</i> Modeling of Ryanodine Receptor 2 Dysfunction Using Human Induced Pluripotent Stem Cells
2011
Background/Aims: Induced pluripotent stem (iPS) cells generated from accessible adult cells of patients with genetic diseases open unprecedented opportunities for exploring the pathophysiology of human diseases in vitro. Catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) is an inherited cardiac disorder that is caused by mutations in the cardiac ryanodine receptor type 2 gene (RYR2) and is characterized by stress-induced ventricular arrhythmia that can lead to sudden cardiac death in young individuals. The aim of this study was to generate iPS cells from a patient with CPVT1 and determine whether iPS cell-derived cardiomyocytes carrying patient specific RYR2 mutation recap…
Three-dimensional cell cultures: from molecular mechanisms to clinical applications.
1997
This article reviews actual advances in the development and application of three-dimensional (3-D) cell culture systems. Recent therapeutically oriented studies include characterization of multicellular-mediated drug resistance, novel ways of quantifying hypoxia, and new approaches to more efficient immunotherapy. Recent progress toward understanding the development of necrosis in tumor spheroids has been made using novel spheroid models. 3-D cultures have been used for studies on molecular mechanisms involved in invasion and metastasis, with a major focus on the role of E-cadherin. Similarly, tumor angiogenesis and the significance of vascular endothelial growth factor have been investigat…
Sodium-glucose cotransporter type 2 inhibitors prevent ponatinib-induced endothelial senescence and disfunction: A potential rescue strategy
2021
Background: Ponatinib (PON), a third-generation tyrosine kinase inhibitor (TKI), has proven cardiovascular toxicity, with no known preventing agents usable to limit such side effect. Sodium-glucose cotransporter type 2 (SGLT2) inhibitors are a new class of glucose-lowering agents, featuring favorable cardiac and vascular effects. Aims: We assessed the effects of the SGLT2 inhibitors empagliflozin (EMPA) and dapagliflozin (DAPA) on human aortic endothelial cells (HAECs) and underlying vasculo-protective mechanisms in an in vitro model of PON-induced endothelial toxicity. Methods and results: We exposed HAECs to PON or vehicle (DMSO) in the presence or absence of EMPA (100 and 500 nmol/L) or …
Genome-wide parent-of-origin DNA methylation analysis reveals the intricacies of human imprinting and suggests a germline methylation-independent mec…
2014
Genomic imprinting is a form of epigenetic regulation that results in the expression of either the maternally or paternally inherited allele of a subset of genes (Ramowitz and Bartolomei 2011). This imprinted expression of transcripts is crucial for normal mammalian development. In humans, loss-of-imprinting of specific loci results in a number of diseases exemplified by the reciprocal growth phenotypes of the Beckwith-Wiedemann and Silver-Russell syndromes, and the behavioral disorders Angelman and Prader-Willi syndromes (Kagami et al. 2008; Buiting 2010; Choufani et al. 2010; Eggermann 2010; Kelsey 2010; Mackay and Temple 2010). In addition, aberrant imprinting also contributes to multige…
MicroRNA-30d deficiency during preconception affects endometrial receptivity by decreasing implantation rates and impairing fetal growth.
2019
Background Maternal–embryonic crosstalk between the endometrium and the preimplantation embryo is required for normal pregnancy. Our previous results demonstrated that maternal microRNAs secreted into the endometrial fluid, specifically miR-30d, act as a transcriptomic regulator of the preimplantation embryo by the maternal intrauterine environment. Objective To investigate the reproductive and fetal effects of murine miR-30d deficiency at the maternal–embryonic interface according to the origin of its maternal or embryonic default. Study Design A miR-30d knockout murine model was used as the animal model to investigate the impact of maternal and/or embryonic origin of miR-30d deficiency on…
Subcellular distribution of choline acetyltransferase by immunogold electron microscopy in non-neuronal cells: Placenta, airways and murine embryonic…
2012
Abstract Aims Acetylcholine is synthesized in more or less all mammalian cells. However, little is known about the subcellular location of acetylcholine synthesis. Therefore, in the present experiments the subcellular location of the synthesizing enzyme choline acetyltransferase (ChAT) was investigated by anti-ChAT immunogold electron microscopy in human placenta and airways as well as in a murine embryonic stem cell line (CGR8 cell line). Main methods Human tissue was obtained as so-called surplus tissue (after delivery/surgical removal because of lung tumor); the CGR8 stem cell line was cultured under standard conditions. For human tissue a monoclonal mouse anti-ChAT antibody (ab) was use…