Search results for " Differentiation"
showing 10 items of 1514 documents
¿Marxismo o diferenciación social?
2018
Para la sociología, el debate con el marxismo forma uno de los telones de fondo intelectuales y prácticos en el surgimiento de esta joven ciencia durante el siglo xix. Uno de los puntos más interesantes de esta disputa trata del grado necesario de diferenciación de las categorías analíticas para comprender los mecanismos básicos de la sociedad. La capacidad y la necesidad de reducir la compl ejidad que requiere cada ciencia, si quiere ll egar a un nivel de generalización que permita la acción social, se contrapone a una diferenciación analítica que tenga en cuenta la máxima cantidad posibl e de elementos relevantes para la comprensión de lo social. El presente artículo alumbra las relacione…
Convergence of Wnt signaling on the HNF4alpha-driven transcription in controlling liver zonation.
2009
Background & Aims: In each hepatocyte, the specific repertoire of gene expression is influenced by its exact location along the portocentrovenular axis of the hepatic lobule and provides a reason for the liver functions compartmentalization defined "metabolic zonation." So far, few molecular players controlling genetic programs of periportal (PP) and perivenular (PV) hepatocytes have been identified; the elucidation of zonation mechanisms remains a challenge for experimental hepatology. Recently, a key role in induction and maintenance of the hepatocyte heterogeneity has been ascribed to Wnt/β-catenin pathway. We sought to clarify how this wide-ranging stimulus integrates with hepatocyte s…
β-Catenin Activation Regulates Tissue Growth Non–Cell Autonomously in the Hair Stem Cell Niche
2014
Coordinated Hair Growth Wnt/β-catenin signaling is a key pathway that plays a conserved role in regulating stem cell function during adult tissue regeneration. Using time-lapse imaging of live mice, Deschene et al. (p. 1353 ) show that genetic activation of β-catenin within hair follicle stem cells generates axes of hair growth by coordinated cell divisions and cell movements, even when the normal niches—the dermal papillae—are laser-ablated. Activated β-catenin enhances Wnt ligand secretion, and these ligands can then activate Wnt signaling in adjacent cells that do not have activated β-catenin, indicating how activated stem cells could influence neighboring cells during normal growth and …
Particles of vaterite, a metastable CaCO3polymorph, exhibit high biocompatibility for human osteoblasts and endothelial cells and may serve as a biom…
2018
We have previously described a promising alternative to conventional synthetic bone biomaterials using vaterite, a metastable CaCO3 polymorph that increases the local Ca2+ concentration in vitro and leads to an oversaturation of phosphate, the primary bone mineral. This stimulates a natural bone-like mineralisation in a short period of time. In this study, sterile and endotoxin-free vaterite particles were synthesised in a nearly quantitative yield. The 500-1,000 nm vaterite particles did not exhibit any cytotoxic effects as measured by MTS, lactate dehydrogenase, or crystal violet assays on the human osteoblast cell line (MG-63) exposed to concentrations up to 500 μg/ml vaterite up to 72 h…
Neural Crest-Derived Chondrocytes Isolation for Tissue Engineering in Regenerative Medicine
2020
Chondrocyte transplantation has been successfully tested and proposed as a clinical procedure aiming to repair articular cartilage defects. However, the isolation of chondrocytes and the optimization of the enzymatic digestion process, as well as their successful in vitro expansion, remain the main challenges in cartilage tissue engineering. In order to address these issues, we investigated the performance of recombinant collagenases in tissue dissociation assays with the aim of isolating chondrocytes from bovine nasal cartilage in order to establish the optimal enzyme blend to ensure the best outcomes of the overall procedure. We show, for the first time, that collagenase H activity alone …
H7, a protein kinase C inhibitor, increases the glutathione content of neuroblastoma cells
1992
AbstractIt is shown that the intracellular glutathione (GSH) concentration of neuroblastoma-2a cells in culture increases with a maximum at 24 h after starting treatment with 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H7), an inhibitor of protein kinase C (PKC). Other inhibitors of this and other protein kinases, e.g. sphingosine, staurosporine, and HA 1004, at the concentrations tested, had a less marked or negligible effect on intracellular GSH concentration. 12-O-Tetradecanoylphorbol-13-acetate (TPA) was also tested and showed no significant effect 24 h after addition.
Human stem cells from single blastomeres reveal pathways of embryonic or trophoblast fate specification.
2015
Mechanisms of initial cell fate decisions differ among species. To gain insights into lineage allocation in humans, we derived ten human embryonic stem cell lines (designated UCSFB1-10) from single blastomeres of four 8-cell embryos and one 12-cell embryo from a single couple. Compared with numerous conventional lines from blastocysts, they had unique gene expression and DNA methylation patterns that were, in part, indicative of trophoblast competence. At a transcriptional level, UCSFB lines from different embryos were often more closely related than those from the same embryo. As predicted by the transcriptomic data, immunolocalization of EOMES, T brachyury, GDF15 and active β-catenin reve…
Type 1 diabetic mellitus patients with increased atherosclerosis risk display decreased CDKN2A/2B/2BAS gene expression in leukocytes
2019
Background Type 1 diabetes mellitus (T1DM) patients display increased risk of cardiovascular disease (CVD) and are characterized by a diminished regulatory T (Treg) cell content or function. Previous studies have shown an association between decreased CDKN2A/2B/2BAS gene expression and enhanced CVD. In the present study the potential relationship between CDKN2A/2B/2BAS gene expression, immune cell dysfunction and increased cardiovascular risk in T1DM patients was explored. Methods A cross-sectional study was performed in 90 subjects divided into controls and T1DM patients. Circulating leukocyte subpopulations analysis by flow cytometry, expression studies on peripheral blood mononuclear cel…
Peroxisome Proliferator-Activated Receptor Deficiency Increases the Risk of Maternal Abortion and Neonatal Mortality in Murine Pregnancy with or with…
2006
We assessed the implication of peroxisome proliferator-activated receptor (PPAR) alpha deficiency in pregnancy outcome and neonatal survival and in the modulation of T cell differentiation in murine diabetic pregnancy and their offspring. Pregnant wild-type (WT) and PPAR alpha-null mice of C57BL/6J genetic background were rendered diabetic by five low doses of streptozotocin. We observed that, in the absence of diabetes, PPAR alpha deficiency resulted in an increase in abortion rate, i.e. 0% in WT mice vs. 20% in PPAR alpha-null mice [odds ratio (OR) = 14.33; P = 0.013]. Under diabetic conditions, the abortion rate was enhanced, i.e. 8.3% in WT mice vs. 50% in PPAR alpha-null mice (OR = 4.2…
Differential roles of cAMP and cGMP in megakaryocyte maturation and platelet biogenesis
2012
The cyclic nucleotides cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) regulate the activity of protein kinase A (PKA) and protein kinase G (PKG), respectively. This process helps maintain circulating platelets in a resting state. Here we studied the role of cAMP and cGMP in the regulation of megakaryocyte (MK) differentiation and platelet formation. Cultured, platelet-producing MKs were differentiated from fetal livers harvested from 13.5 days postcoital mouse embryos. MK development was accompanied by a dramatic increase in cAMP production and expression of soluble guanylate cyclase, PKG, and PKA as well as their downstream targets vasodilator-stimulated ph…