Staurosporine blocked normal cells at G1/S boundary.
(57/31967)
AIM: To reveal the regulating difference of G1/S-phase transition between normal and tumor cells by using staurosporine, an unspecific kinase inhibitor. METHODS: Flow cytometry, Dot blot, kinase activity assay, and electrophoresis. RESULTS: A 18-h treatment with staurosporine (5 micrograms.L-1) blocked normal cell line 2BS cells (normal human embryonic lung fibroblast, 5-20 passages) in G1 phase, decreased their thymidine kinase (TK) mRNA level and activity, and also dephosphorylated an intracellular 107 kDa protein. Meanwhile, all these effects in 2BS cells disappeared only by washing staurosporine away. Such kind of effects did not occur in tumor cell line BGC-823 cells (human stomach cancer cell). CONCLUSION: During the period of G1/S-phase transition, the kinases involved are more sensitive to staurosporine in normal cells than in tumor cells. (+info)
Effects of dexamethasone and ibuprofen on LPS-induced gene expression of TNF alpha, IL-1 beta, and MIP-1 alpha in rat lung.
(58/31967)
AIM: To study the kinetics of tumor necrosis factor alpha (TNF alpha), interleukine-1 (IL-1 beta), and macrophage inflammatory protein-1 alpha (MIP-1 alpha) gene expression in rat lung after i.p. lipopolysaccharides (LPS) and the effect of dexamethasone (Dex) and ibuprofen (Ibu) on the cytokines gene expression. METHODS: The amount of Evans blue in lung was measured by fluorescence method. The mRNA levels of TNF alpha, IL-1 beta, and MIP-1 alpha in rat lung were assessed by slot blot analysis. RESULTS: The mRNA levels of TNF alpha, IL-1 beta, and MIP-1 alpha in rat lung after i.p. LPS increased in a dose-dependent manner, and peaked at 2, 6, and 12 h, respectively. Both Dex 50 mg.kg-1 and Ibu 90 mg.kg-1 injected at 1 h before i.p. LPS markedly decreased the content of Evans blue in lung at 1 h after i.p. LPS. After Dex or Ibu pretreatment, the peak levels of TNF alpha, IL-1 beta, and MIP-1 alpha mRNA decreased markedly compared with LPS alone. CONCLUSION: The gene expression of TNF alpha, IL-1 beta, and MIP-1 alpha in rat lung increased after i.p. LPS. Dex and Ibu prevented LPS-induced lung injury through inhibiting the cytokines gene expression. (+info)
Isolation and characterization of Dobrava hantavirus carried by the striped field mouse (Apodemus agrarius) in Estonia.
(59/31967)
Dobrava hantavirus (DOB) was isolated from the striped field mouse (Apodemus agrarius) trapped on Saaremaa Island, Estonia, and its genetic and antigenic characteristics were subsequently analysed. Phylogenetic analysis showed that the Estonian DOB strain, together with several wild strains carried by Apodemus agrarius, forms a well-supported lineage within the DOB clade. The topography of the trees calculated for the S, M and L nucleotide sequences of the Estonian DOB suggests a similar evolutionary history for all three genes of this virus and, therefore, the absence of heterologous reassortment in its evolution. A cross-neutralization comparison of the Estonian virus with the prototype DOB, isolated from a yellow-necked mouse (A. flavicollis) in Slovenia, revealed 2- to 4-fold differences in the end-point titres of rabbit and human antisera. When studied with a panel of 25 monoclonal antibodies (MAbs), the Estonian and Slovenian DOB isolates showed similar antigenic patterns that could be distinguished by two MAbs. Genetic comparison showed sequence differences in all three genome segments of the two DOB isolates, including an additional N-glycosylation site in the deduced sequence of the G2 protein from the Estonian virus. Whether any of these mutations relates to the different rodent hosts rather than to the distant geographical origin of the two isolates remains to be resolved. Taken together, our observations suggest that A. agrarius, which is known to harbour Hantaan virus in Asia, carries another hantavirus, DOB, in north-east Europe. (+info)
Immunological control of a murine gammaherpesvirus independent of CD8+ T cells.
(60/31967)
Adult thymectomized C57 BL/6J mice were depleted of T cell subsets by MAb treatment either prior to, or after, respiratory challenge with murine gammaherpesvirus-68. Protection against acute infection was maintained when either the CD4+ or the CD8+ T cell population was greatly diminished, whereas the concurrent removal of both T cell subsets proved invariably fatal. The same depletions had little effect on mice with established infection. The results indicate firstly that both CD4+ and CD8+ T cells play a significant part in dealing with the acute infection, and secondly that virus-specific antibody contributes to controlling persistent infection with this gammaherpesvirus. (+info)
Conserved function of mSpry-2, a murine homolog of Drosophila sprouty, which negatively modulates respiratory organogenesis.
(61/31967)
In Drosophila embryos, the loss of sprouty gene function enhances branching of the respiratory system. Three human sprouty homologues (h-Spry1-3) have been cloned recently, but their function is as yet unknown [1]. Here, we show that a murine sprouty gene (mSpry-2), the product of which shares 97% homology with the respective human protein, is expressed in the embryonic murine lung. We used an antisense oligonucleotide strategy to reduce expression of mSpry-2 by 96%, as measured by competitive reverse transcriptase PCR, in E11. 5 murine embryonic lungs cultured for 4 days [2]. Morphologically, the decrease in mSpry-2 expression resulted in a 72% increase in embryonic murine lung branching morphogenesis as well as a significant increase in expression of the lung epithelial marker genes SP-C, SP-B and SP-A. These results support a striking conservation of function between the Drosophila and mammalian sprouty gene families to negatively modulate respiratory organogenesis. (+info)
Prenatal nicotine increases pulmonary alpha7 nicotinic receptor expression and alters fetal lung development in monkeys.
(62/31967)
It is well established that maternal smoking during pregnancy is a leading preventable cause of low birth weight and prematurity. Less appreciated is that maternal smoking during pregnancy is also associated with alterations in pulmonary function at birth and greater incidence of respiratory illnesses after birth. To determine if this is the direct result of nicotine interacting with nicotinic cholinergic receptors (nAChRs) during lung development, rhesus monkeys were treated with 1 mg/kg/day of nicotine from days 26 to 134 of pregnancy. Nicotine administration caused lung hypoplasia and reduced surface complexity of developing alveoli. Immunohistochemistry and in situ alpha-bungarotoxin (alphaBGT) binding showed that alpha7 nAChRs are present in the developing lung in airway epithelial cells, cells surrounding large airways and blood vessels, alveolar type II cells, free alveolar macrophages, and pulmonary neuroendocrine cells (PNEC). As detected both by immunohistochemistry and by alphaBGT binding, nicotine administration markedly increased alpha7 receptor subunit expression and binding in the fetal lung. Correlating with areas of increased alpha7 expression, collagen expression surrounding large airways and vessels was significantly increased. Nicotine also significantly increased numbers of type II cells and neuroendocrine cells in neuroepithelial bodies. These findings demonstrate that nicotine can alter fetal monkey lung development by crossing the placenta to interact directly with nicotinic receptors on non-neuronal cells in the developing lung, and that similar effects likely occur in human infants whose mothers smoke during pregnancy. (+info)
Transcription of the adenine nucleotide translocase isoforms in various types of tissues in the rat.
(63/31967)
Two different isoforms of the adenine nucleotide translocase (ANT1 and ANT2) have been identified in the rat. In order to obtain enhanced knowledge of the ANT isoform expression, we analyzed the transcription pattern of both isoforms and their mRNA levels in various tissues of the rat using the PCR technique. A predominant ANT1 mRNA percentage was recorded in the skeletal muscle, heart and brain, ranging from 81 to 58%. In contrast to these tissues, the percentages of ANT2 were dominant with a range from 59 to 75% in the kidney, lung, spleen and liver. The level of total ANT mRNA varied markedly in the various organs. Tissues with a dominant ANT1 percentage simultaneously showed a high level of total ANT transcription (24-41 attomol/ng total RNA). In comparison to the latter, tissues with a prevalent ANT2 transcription were shown to have an even lower ANT transcription level (2-5 attomol/ng total RNA). The predominance of the ANT1 expression appeared to be restricted to tissues with an inability to regenerate by means of mitotic division, whereas a prevalent ANT2 transcription is found in cell types able to proliferate. The level of total ANT transcription but not the individual ANT isoform expression depends to a great extent on the energy requirements of the tissue. (+info)
Tissue-specific changes of type 1 angiotensin II receptor and angiotensin-converting enzyme mRNA in angiotensinogen gene-knockout mice.
(64/31967)
This study examined whether type 1 angiotensin II receptor (AT1) and angiotensin-converting enzyme (ACE) mRNAs are regulated during dietary salt loading in angiotensinogen gene-knockout (Atg-/-) mice which are genetically deficient in endogenous production of angiotensin II. Wild-type (Atg+/+) and Atg-/- mice were fed a normal-salt (0.3% NaCl) or a high-salt (4% NaCl) diet for 2 weeks. The mRNA levels were measured by Northern blot analysis. In Atg+/+ mice, concentrations of plasma angiotensin peptides were decreased by salt loading, whereas the treatment increased the brainstem, cardiac, pulmonary, renal cortex, gastric and intestinal AT1 mRNA levels. Salt loading also enhanced renal cortex ACE mRNA levels in Atg+/+ mice. Although plasma angiotensin peptides and urinary aldosterone excretion were not detected in Atg-/- mice, salt loading increased blood pressure in Atg-/- mice. In Atg-/- mice, pulmonary, renal cortex, gastric and intestinal AT1, and renal cortex and intestinal ACE mRNA levels were higher than those in Atg+/+ mice. However, salt loading upregulated AT1 mRNA expression only in the liver of Atg-/- mice, and the treatment did not affect ACE mRNA levels in Atg-/- mice. Furthermore, although the levels of ACE enzymatic activity showed the same trend with the ACE mRNA levels in the lung, renal cortex and intestine of both Atg-/- and Atg+/+ mice, the results of radioligand binding assay showed that cardiac expression of AT1 protein was regulated differently from AT1 mRNA expression both in Atg-/- and Atg+/+ mice. Thus, expression of AT1 and ACE is regulated by salt loading in a tissue-specific manner that appears to be mediated, at least partly, by a mechanism other than changes in the circulating or tissue levels of angiotensin peptides. (+info)