Aluminum Ions Induce DNA Synthesis But Not Cell Proliferation in Human Fibroblasts In Vitro

2002 ◽  
Vol 86 (1) ◽  
pp. 01-10 ◽  
Author(s):  
Carmen Domínguez ◽  
Antonio Moreno ◽  
Marc Llovera
Keyword(s):  
Cell Proliferation ◽  
Dna Synthesis ◽  
Human Fibroblasts ◽  
Aluminum Ions

scholarly journals Insulin Stimulates Goose Liver Cell Growth by Activating PI3K-AKT-mTOR Signal Pathway

2016 ◽  
Vol 38 (2) ◽  
pp. 558-570 ◽  
Author(s):  
Chunchun Han ◽  
Shouhai Wei ◽  
Qi Song ◽  
Fang He ◽  
Xiangping Xiong ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Synthesis ◽  
Protein Content ◽  
Mrna Level ◽  
Signal Pathway ◽  
Mtor Pathway ◽  
Brdu Incorporation ◽  
Primary Hepatocytes

Background/Aims: Recent studies have suggested a crucial role for PI3K-Akt-mTOR pathway in regulating cell proliferation, so we hypothesize that insulin acts goose hepatocellular growth by PI3K-Akt-mTOR signal pathway. Because the physiological status of liver cells in vitro is different from that in vivo, a simplified cell model in vitro was established. Methods: Goose primary hepatocytes were isolated and incubated in either no addition as a control or insulin or PI3K-Akt-mTOR pathway inhibitors or co-treatment with glucose and PI3K-Akt-mTOR pathway inhibitors; Then, cell DNA synthesis and cell cycle analysis were detected by BrdU-incorporation Assay and Flow cytometric analysis; the mRNA expression and protein expression of factors involved in the cell cycle were determined by Real-Time RT-PCR, ELISA, and western blot. Results: Here we first showed that insulin evidently increased the cell DNA synthesis, the mRNA level and protein content of factors involved in the cell proliferation of goose primary hepatocytes. Meanwhile, insulin evidently increased the mRNA level and protein content of factors involved in PI3K-Akt-mTOR pathway. However, the up-regulation of insulin on cell proliferation was decreased significantly by the inhibitors of PBK-Akt-mTOR pathway, LY294002, rapamycin or NVP-BEZ235. Conclusion: These findings suggest that PI3K-Akt-mTOR pathway plays an essential role in insulin-regulated cell proliferation of goose hepatocyte.

Inhibition of pig granulosa cell adhesion and growth in vitro by immunoneutralization of epithelial cadherin

Reproduction ◽  
2000 ◽  
pp. 275-281 ◽  
Author(s):  
KM Kirkup ◽  
AM Mallin ◽  
CA Bagnell
Keyword(s):  
Cell Proliferation ◽  
Cell Adhesion ◽  
Dna Synthesis ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Contact ◽  
Mouse Ascites ◽  
Proliferation In Vitro ◽  
E Cadherin

Epithelial cadherin (E-cadherin) is a member of the cadherin family of calcium-dependent cell adhesion molecules and is present in the ovary. Although expression of E-cadherin is high in healthy pig granulosa cells and low in granulosa cells of atretic follicles, the importance of E-cadherin-mediated adhesion in granulosa cell function is unclear. The aim of the present study was to determine the impact of immunoneutralization of E-cadherin on granulosa cell adhesion, DNA synthesis and cell proliferation in vitro. Before attachment, pig granulosa cells were exposed to a monoclonal E-cadherin antibody (DECMA-1) which blocks E-cadherin function. Controls included substitution of the antibody with either mouse ascites fluid or another E-cadherin antibody directed against the cytoplasmic domain and which was therefore inaccessible in intact cells. Both granulosa cell proliferation and insulin-like growth factor I-induced DNA synthesis were inhibited significantly in the presence of DECMA-1 compared with controls (P < 0.05). Control granulosa cells in culture formed large clusters with many cells packed tightly together. However, after 48 h exposure to the function-perturbing E-cadherin antibody, there was a significant decrease in the size of the granulosa cell clusters (P < 0.05) and the degree of cell-cell contact was reduced compared with control cultures. No effects on DNA synthesis, cell proliferation or cell adhesion were observed when DECMA-1 was substituted with either mouse ascites fluid or the antibody specific for the cytoplasmic domain of E-cadherin. In conclusion, these data provide evidence to support the hypothesis that E-cadherin is important for maintaining granulosa cell contact, DNA synthesis and cell proliferation in vitro. These results indicate that E-cadherin plays a fundamental role in maintaining both the structure and function of ovarian follicles.

scholarly journals Monoclonal antibody to the thrombin receptor stimulates DNA synthesis in combination with gamma-thrombin or phorbol myristate acetate.

1987 ◽  
Vol 105 (6) ◽  
pp. 2551-2558 ◽  
Author(s):  
G H Frost ◽  
W C Thompson ◽  
D H Carney
Keyword(s):  
Monoclonal Antibody ◽  
Cell Proliferation ◽  
Dna Synthesis ◽  
Human Fibroblasts ◽  
Enzymic Activity ◽  
Thrombin Receptor ◽  
High Affinity ◽  
Thrombin Receptors ◽  
Affinity Interaction

Studies with various thrombin derivatives have shown that initiation of cell proliferation by thrombin requires two separate types of signals: one, generated by high affinity interaction of thrombin or DIP-thrombin (alpha-thrombin inactivated at ser 205 of the B chain by diisopropylphosphofluoridate) with receptors and the other, by thrombin's enzymic activity. To further study the role of high affinity thrombin receptors in initiation, we immunized mice with whole human fibroblasts and selected antibodies that blocked the binding of 125I-thrombin to high affinity receptors on hamster fibroblasts. One of these antibodies, TR-9, inhibits from 80 to 100% of 125I-thrombin binding, exhibits an immunofluorescent pattern indistinguishable from that of thrombin bound to receptors on these cells, and selectively binds solubilized thrombin receptors. By itself, TR-9 did not initiate DNA synthesis nor did it block thrombin initiation, but TR-9 addition to cells in the presence of alpha-thrombin, gamma-thrombin (0.5 microgram/ml), or PMA stimulated thymidine incorporation up to threefold over controls. In all cases, maximal stimulation was observed at concentrations of TR-9, ranging from 1 to 4 nM corresponding to concentrations required to inhibit from 30 to 100% of 125I-thrombin binding. These results demonstrate that the binding of the monoclonal antibody to the alpha-thrombin receptor can mimic the effects of thrombin's high affinity interaction with this receptor in stimulating cell proliferation.

scholarly journals hDREF Regulates Cell Proliferation and Expression of Ribosomal Protein Genes

2007 ◽  
Vol 27 (6) ◽  
pp. 2003-2013 ◽  
Author(s):  
Daisuke Yamashita ◽  
Yukako Sano ◽  
Yuka Adachi ◽  
Yuma Okamoto ◽  
Hirotaka Osada ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Ribosomal Proteins ◽  
Human Fibroblasts ◽  
Gene Promoter ◽  
Ribosomal Protein Genes ◽  
Mobility Shift ◽  
Positive Elements

ABSTRACT Although ribosomal proteins (RPs) are essential cellular constituents in all living organisms, mechanisms underlying regulation of their gene expression in mammals remain unclear. We have established that 22 out of 79 human RP genes contain sequences similar to the human DREF (DNA replication-related element-binding factor; hDREF) binding sequence (hDRE) within 200-bp regions upstream of their transcriptional start sites. Electrophoretic gel mobility shift assays and chromatin immunoprecipitation analysis indicated that hDREF binds to hDRE-like sequences in the RP genes both in vitro and in vivo. In addition, transient luciferase assays revealed that hDRE-like sequences act as positive elements for RP gene transcription and cotransfection of an hDREF-expressing plasmid was found to stimulate RP gene promoter activity. Like that of hDREF, expression of RP genes is increased during the late G1 to S phases, and depletion of hDREF using short hairpin RNA-mediated knockdown decreased RP gene expression and cell proliferation in normal human fibroblasts. Knockdown of the RPS6 gene also resulted in impairment of cell proliferation. These data suggest that hDREF is an important transcription factor for cell proliferation which plays roles in cell cycle-dependent regulation of a number of RP genes.

Gastric mucosal cell proliferation during development in rats and effects of pentagastrin

1982 ◽  
Vol 242 (2) ◽  
pp. G135-G139 ◽  
Author(s):  
A. P. Majumdar ◽  
L. R. Johnson
Keyword(s):  
Cell Proliferation ◽  
Dna Synthesis ◽  
Thymidine Kinase ◽  
Kinase Activity ◽  
Cell Loss ◽  
Saline Control ◽  
Mucosal Cell ◽  
Thymidine Kinase Activity ◽  
Old Rats

Changes in cell proliferation and cell loss in the gastric mucosa were examined during the first 4 wk of life. The effect of pentagastrin on these parameters before and after weaning was also investigated. The results revealed that DNA content of mucosa and lumen increased with age. However, when luminal DNA (an assessment of cell loss) content was expressed as percent of total mucosal DNA (referred to as percent cell loss), an inverse relationship with age was observed. The rate of mucosal DNA synthesis, measured in vitro, was found to remain elevated up to the age of 15 days and then dropped dramatically within the next 5--6 days after which it decreased slowly. The rate of mucosal DNA synthesis in 5- to 15-day-old rats was found to be 10--15 times higher than in 20- to 30-day-old rats. In 10-day-old suckling young, mucosal thymidine kinase activity was also found to be higher than in 20- to 28-day-old rats. On the other hand, total incorporation of [3H]thymidine into mucosal DNA per stomach was found to be significantly greater in 21- to 28-day-old weaned rats than in the 10-day-old suckling young. Multiple injections of pentagastrin to 28-day-old rats significantly increased mucosal DNA synthesis and thymidine kinase activity by 43 and 200%, respectively, and cell loss by 30% when compared with the saline control. The hormone did not affect DNA synthesis, thymidine kinase, or cell loss in 10-day-old rats. There were considerable increases in 20-day-old rats that were not statistically significant due to the variation of the data.

scholarly journals Cytotoxicity analysis of electrostatically applied epoxy coating onto CO-CR alloy

2015 ◽  
Vol 63 (3) ◽  
pp. 257-262 ◽  
Author(s):  
Êrica Wehmuth RAGONHA ◽  
Elizabeth Ferreira MARTINEZ ◽  
Carlos Alberto MUZILLI ◽  
Milton Edson MIRANDA ◽  
Karina Andrea Novaes OLIVIERI
Keyword(s):  
Cell Proliferation ◽  
Human Fibroblasts ◽  
Metal Structure ◽  
In Vitro Cytotoxicity ◽  
Control Surface ◽  
Cobalt Chromium ◽  
Cell Counts ◽  
Manual Counting ◽  
Significant Difference

Objective: To investigate the biological effect of a new method to camouflage the cobalt-chromium (CoCr) metal structure of an RPD, onto which an electrostatic paint was applied. Methods: In vitro cytotoxicity of epoxy Politherm NOBAC30C (Weg Industries SA, Santa Catarina, Brazil) in combination with polished CoCr was tested by placing it in contact with cultured human fibroblasts and comparing it with polystyrene (control surface). The cells were cultured in the presence of the test surfaces for 24, 48, 72, 94 and 120 hours. The number of viable and non-viable cells was established by manual counting. The Tukey test was used to statistically analyze cell counts between the groups. Results: The results showed that cell proliferation was similar between the groups (p =0.2174). It was observed that at 24, 48 and 72 h, there was no significant increase in cell proliferation in all groups. From 96 to 120 h, an increase in cell proliferation was observed in all groups, with no significant difference between them (p>0.05). Conclusion: The epoxy paint studied showed no cytotoxicity in vitro.

Cell proliferation is not required for the initiation of early cleft formation in mouse embryonic submandibular epithelium in vitro

Development ◽  
1987 ◽  
Vol 99 (3) ◽  
pp. 429-437 ◽  
Author(s):  
Y. Nakanishi ◽  
T. Morita ◽  
H. Nogawa
Keyword(s):  
Cell Proliferation ◽  
Dna Synthesis ◽  
Specific Inhibitor ◽  
X Rays ◽  
X Ray ◽  
Mitotic Figures ◽  
Cleft Formation ◽  
Proliferation In Vitro

An X-ray irradiation method was employed to analyse the role of cell proliferation in vitro in the cleft formation of mouse embryonic submandibular epithelium at early stages. When the mid 12-day gland was exposed to 200 rad of X-rays, the growth was severely retarded. In contrast, late 12-day and early 13-day glands grew apparently in a normal fashion, as did the control gland, for up to 40 h. In either case, they formed shallow clefts within 10 h of culture. With 1000 rad irradiation, the mid 12-day gland did not grow at all, but formed clefts within 20 h of culture followed by a rapid degeneration. Under the same conditions, the growth of the late 12-day gland, which was at the stage just before branching, was retarded until 10 h of culture, followed by a slight increase in epithelial size, but cleft formation was also observed within 6–10 h, as in the control gland. When exposed to a dose of 1000 rad of X-rays, the early 13-day and the late 12-day glands exhibited similar radiosensitivity; the initial narrow clefts in the epithelium deepened and new clefts began to form within 6–10 h of culture. [3H]thymidine incorporation studies revealed that a dose of 1000 rad reduced DNA synthesis of mid and late 12-day glands by 72 and 65%, respectively. Histological examination of X-irradiated late 12-day gland showed that mitotic figures were rarely seen in the epithelium at 6 h of culture. Aphidicolin, a specific inhibitor of DNA synthesis, could not halt the cleft formation of the late 12-day gland. In this experiment 89% of DNA synthesis was inhibited. Treatment of an X-ray irradiated late 12-day gland with aphidicolin blocked 92% of the DNA synthesis, but did not prevent cleft formation taking place. These results indicate that neither cell division nor DNA synthesis, is required for the initiation process of the cleft formation of the mouse embryonic submandibular epithelium at early morphogenetic stages in vitro.

Sign in / Sign up

Export Citation Format

Share Document