Search results for "Cell Differentiation"
showing 10 items of 907 documents
Fetal calf serum and retinoic acid affect proliferation and terminal differentiation of a rat rhabdomyosarcoma cell line (BA-HAN-1C)
1989
We report on the establishment of a model for differentiation induction in sarcomas, using the clonal rhabdomyosarcoma cell line BA-HAN-1C. This rhabdomyosarcoma cell line is composed of morphologically undifferentiated mononuclear stem cells, some of which spontaneously fuse to form terminally differentiated multinuclear myotube-like giant cells. The deprivation of fetal calf serum (FCS) or the exposure to retinoic acid, respectively, resulted in a significant inhibition of proliferation (P less than 0.001) and a marked increase in cellular differentiation as shown by a significant increase in the number of myotube-like giant cells (P less than 0.001) and in the creatine kinase activity (P…
Do not stress, just differentiate: role of stress proteins in hematopoiesis
2015
Hematopoiesis permits the constant regeneration of the blood system and is a permanent example of cell differentiation. Defects in its tight regulation can lead to either cell death or abnormal proliferation and may translate into multiple types of blood disorders, including leukemia. Heat shock proteins (HSPs), the expression of which is controlled by heat shock factors (HSFs, currently four known members),1 are a set of highly conserved proteins induced in response to a wide variety of physiological and environmental stress. HSP/HSF overexpression or mislocalization has been described in many cancers, particularly in hematology, and other diseases. Therefore, the involvement of HSFs/HSPs …
Synaptophysin expressed in the bronchopulmonary tract: neuroendocrine cells, neuroepithelial bodies, and neuroendocrine neoplasms.
1987
Synaptophysin is an integral membrane glycoprotein with an Mr of 38,000 that occurs in the small, clear vesicles present in neuronal cells and tumors as well as in pancreatic islet cells and various neuroendocrine (NE) carcinomas. We found that synaptophysin is also expressed in normal NE cells of the lungs of newborn rabbits and mice as well as of human fetuses. In bronchial ganglion cells and in nerves, synaptophysin is coexpressed with neurofilament proteins (NFPs), whereas in solitary NE cells and in at least some of the neuroepithelial bodies (NEBs) of the bronchial mucosal lining, synaptophysin coexists with cytokeratins. We also studied a series of NE neoplasms of the lung covering t…
mTOR Inhibition Improves Antitumor Effects of Vaccination with Antigen-Encoding RNA
2013
Abstract Vaccination with in vitro transcribed RNA encoding tumor antigens is an emerging approach in cancer immunotherapy. Attempting to further improve RNA vaccine efficacy, we have explored combining RNA with immunomodulators such as rapamycin. Rapamycin, the inhibitor of mTOR, was used originally for immunosuppression. Recent reports in mouse systems, however, suggest that mTOR inhibition may enhance the formation and differentiation of the memory CD8+ T-cell pool. Because memory T-cell formation is critical to the outcome of vaccination aproaches, we studied the impact of rapamycin on the in vivo primed RNA vaccine-induced immune response using the chicken ovalbumin-expressing B16 mela…
The Endocannabinoid System Promotes Astroglial Differentiation by Acting on Neural Progenitor Cells
2006
Endocannabinoids exert an important neuromodulatory role via presynaptic cannabinoid CB1receptors and may also participate in the control of neural cell death and survival. The function of the endocannabinoid system has been extensively studied in differentiated neurons, but its potential role in neural progenitor cells remains to be elucidated. Here we show that the CB1receptor and the endocannabinoid-inactivating enzyme fatty acid amide hydrolase are expressed, bothin vitroandin vivo, in postnatal radial glia (RC2+cells) and in adult nestin type I (nestin+GFAP+) neural progenitor cells. Cell culture experiments show that CB1receptor activation increases progenitor proliferation and differ…
Degenerative and regenerative processes involved in midgut pseudotumor formation in the stick insect (Carausius morosus)
2009
Spontaneous and experimentally induced pseudotumor formation in Carausius morosus impairs the midgut tissue homeostasis. Spontaneous pseudotumor formation begins by the break down of a single or a small group of columnar cells (CCs) and is followed by the degeneration of neighboring CCs. There are not only marked similarities but also decisive differences between normal dying CCs in healthy specimens and the degeneration of CCs leading to pseudotumors: in both cases, the apical cell parts with the nucleus are extruded into the midgut lumen, but only during of pseudotumor formation an "amorphous substance" originates from the basal parts of the CCs. Hemocytes are attracted to this substance …
Human Embryonic Stem Cell Derived Hepatocyte-Like Cells as a Tool for In Vitro Hazard Assessment of Chemical Carcinogenicity
2011
Hepatocyte-like cells derived from the differentiation of human embryonic stem cells (hES-Hep) have potential to provide a human relevant in vitro test system in which to evaluate the carcinogenic hazard of chemicals. In this study, we have investigated this potential using a panel of 15 chemicals classified as noncarcinogens, genotoxic carcinogens, and nongenotoxic carcinogens and measured whole-genome transcriptome responses with gene expression microarrays. We applied an ANOVA model that identified 592 genes highly discriminative for the panel of chemicals. Supervised classification with these genes achieved a cross-validation accuracy of > 95%. Moreover, the expression of the response g…
Can Hepatoma Cell Lines be Re-differentiated to be Used in Drug Metabolism Studies?
2013
Knowledge of metabolism, enzymes so far involved, and potential enzyme-inhibiting or enzyme-inducing properties of new compounds is a key issue in drug development. Primary cultured hepatocytes, cytochrome P450 (CYP)-engineered cells and hepatoma cell lines are currently being used for this purpose, but only primary cultures can produce a metabolic profile of a drug similar to that found in vivo and can respond to inducers. Because of their limited accessibility, alternatives to replace human hepatocytes are currently being explored, including the immortalisation of hepatocytes by using different strategies (i.e. SV40 T-large antigen, conditionally immortalised hepatocytes, transfection wi…
Adipose Stromal Vascular Fraction Improves Cardiac Function in Chronic Myocardial Infarction Through Differentiation and Paracrine Activity
2012
Fresh adipose-derived cells have been shown to be effective in the treatment of acute myocardial infarction (MI), but their role in the chronic setting is unknown. We sought to determine the long-term effect of the adipose derived-stromal vascular fraction (SVF) cell transplantation in a rat model of chronic MI. MI was induced in 82 rats by permanent coronary artery ligation and 5 weeks later rats were allocated to receive an intramyocardial injection of 107 GFP-expressing fresh SVF cells or culture media as control. Heart function and tissue metabolism were determined by echocardiography and 18F-FDG-microPET, respectively, and histological studies were performed for up to 3 months after t…
Biostable Scaffolds of Polyacrylate Polymers Implanted in the Articular Cartilage Induce Hyaline-Like Cartilage Regeneration in Rabbits
2017
[EN] Purpose: To study the influence of scaffold properties on the organization of ¿in vivo¿ cartilage regeneration. Our hypothesis is that stress transmission to the cells seeded inside the scaffold pores or surrounding it, which is highly dependent on the scaffold properties, determine differentiation of both mesenchymal cells and dedifferentiated autologous chondrocytes. Methods: Four series of porous scaffolds made of different polyacrylate polymers, previously seeded with cultured rabbit chondrocytes or without cells preseeded, were implanted in cartilage defects in rabbits. Subchondral bone was always injured during the surgery in order to allow blood to reach the implantation site an…