Cell culture

About: Cell culture is a research topic. Over the lifetime, 133361 publications have been published within this topic receiving 5364150 citations. The topic is also known as: cell culture techniques.

The role of depolarization in the survival and differentiation of cerebellar granule cells in culture

Abstract: Cultures greatly enriched in granule cells from early postnatal cerebellum (P8) were grown in a medium containing fetal calf serum. Under the conditions used, nerve cells died, usually within a week, unless the K+ concentration in the medium was greater than or equal to 20 mM. The requirement for elevated [K+]e was manifested by about 3 d in vitro, and after this time continuous exposure to high [K+]e was essential for the survival of the granule cells. The initial morphological and biochemical maturation of the granule cells was similar in the presence and the absence of elevated [K+]e, suggesting that the dependence on depolarizing conditions develops in parallel with the expression of the differentiated characteristics of the cells. The positive effect of elevated [K+]e on granule cell survival was not influenced by preventing bioelectric activity in the cultures with TTX and xylocaine. On the other hand, depolarization-induced transmembrane Ca2+ flux was essential in securing the maintenance of the granule cells. Depolarized nerve cells were compromised when Ca2+ entry was blocked by elevated Mg2+, EGTA, or organic Ca2+ antagonists, while dihydropyridine Ca2+ agonists [BAY K 8644, (+)-(S)-202 79 1 and CGP 28392] were potent agents preventing nerve cell loss in the presence of 15 mM [K+]e, which was ineffective on its own. Calmodulin inhibitors (1 microM trifluoperazine or calmidazolium) blocked the beneficial effect of K+-induced depolarization on granule cells. The comparison of the timing of the differentiation and innervation of the postmitotic granule cells in vivo with the development of the K+ dependence in vitro would indicate that depolarization of the granule neurons in culture mimics the influence of the physiological stimulation in vivo through excitatory amino acid receptors, including N-methyl-D-aspartate receptors, involving Ca2+ entry and the activation of a Ca2+/calmodulin- dependent protein kinase.

cDNA sequence and chromosomal localization of human platelet-derived growth factor A-chain and its expression in tumour cell lines

Abstract: The amino-acid sequence of the precursor of the human tumour cell line-derived platelet-derived growth factor (PDGF) A-chain has been deduced from complementary DNA clones and the gene localized to chromosome 7. The protein shows extensive homology to the PDGF B-chain precursor. Expression of the PDGF A-chain gene is independent of that of the PDGF B-chain in a number of human tumour cell lines, and secretion of a PDGF-like growth factor of relative molecular mass 31,000 correlates with expression of A- but not B-chain messenger RNA.

Culture of Normal Human Leukocytes

Abstract: Rapidly growing and apparently permanent cultures were established from hematopoietic cells from two staff members with no known malignant disease. The cell lines were similar to those derived from leukocytes from the peripheral blood of patients with malignancies of either hematopoietic or nonhematopoietic origin and to the lymphoblastoid cell lines derived from Burkitt's lymphoma. Both cell lines contained a herpetic-like virus (leukovirus), produced immunoglobulins, and grew rapidly in various suspension cultures.

Role of the HTLV-III/LAV envelope in syncytium formation and cytopathicity.

Abstract: Acquired immune deficiency syndrome (AIDS) is characterized by marked depletion of the T4+ helper subset of T cells. The aetiological agent of the disease, the human T-lymphotropic virus type III (HTLV-III)/lymphadenopathy-associated virus (LAV), specifically kills T4+ cells in vitro. Part of this specificity for the T4+ population residues in the relative efficiency with which HTLV-III infects these cells, as a result of a specific interaction between the T4 molecule and the virus envelope glycoprotein. In addition, the cytotoxic consequences of HTLV-III replication are dependent on cell type, as certain lymphoid and myeloid cells can be productively infected without notable cytopathic effect. Here we investigate the basis for the specific cytotoxicity of the virus, and report that high-level expression of the HTLV-III envelope gene induces syncytia and concomitant cell death in T4+ cell lines but not in a B-lymphocyte line. Syncytium formation depends on the interaction of envelope-expressing cells with neighbouring cells bearing surface T4 molecules. These results explain, at least in part, the specific cytopathic effect of HTLV-III infections.