Cytokinesis ; Micronucleus Tests

The advance of experimental cell division and proliferation in the field of cell biomechanics is presented in this paper. The emphasis is placed on the research in the mechanics mechanism of cleavage furrow and in the measurement of constricting force about cleavage furrow.
Biomechanical Phenomena ; Cell Division ; physiology ; Cytokinesis ; physiology ; Humans

A lot of experimental findings have confirmed that: Animal cells acquire a spherical shape just before the division; Under biochemical stimulus of mitotic apparatus aster the cells form a contractile ring in equator plane, and the mother cell divides into two daughter cells; meanwhile the total volume keeps constant. In Zinemanas and Nir's model the reorientation of microfilament and the visco-elasticity of cortex have been took into consideration. In our present work, the effective coefficient m due to biochemical stimulus was incorporated into the model, and the local distribution C was modified to diffuse with the plasma membrane motion. The numerical results showed that the formation of a contractile ring and parameters such as the surface tension in the furrow and internal pressure can be predicted successfully. Compared with Zinemanas and Nir's model, the results of our model are more correspondent with the experimental results. It can be concluded that the effective coefficient m has limited effects on the process control of cytokinesis.
Animals ; Biomechanical Phenomena ; Cytokinesis ; Humans ; Models, Biological ; Surface Tension

Cytokinesis ; Humans ; Lymphocytes ; pathology ; Micronucleus Tests ; Neoplasms ; genetics ; Risk Factors

BACKGROUND: Aurora kinase A (Aurora-A) plays an important role in the regulation of mitosis and cytokinesis. Dysregulated Aurora-A leads to mitotic faults and results in pathological conditions. No studies on Aurora-A expression in human diabetic skin tissue have been reported. In light of this, we explored the expression of Aurora-A in human diabetic skin tissue. METHODS: Aurora-A protein was evaluated by western blotting in 6 human diabetic skin tissue and 6 normal skin specimens. RESULTS: Increased expression of Aurora-A protein was detected in all diabetic skin tissue samples in both western blot analysis and immunohistochemical staining. However, in the case of the normal skin tissue, no bands of Aurora-A protein were detected in either the western blotting analysis or the immunohistochemical staining. CONCLUSIONS: Thus far, there have been no studies on the expression of Aurora-A in diabetic skin tissue. However, we believe that oxidative DNA damage related to the expression of Aurora-A protein and Aurora-A could be involved inhuman diabetic skin tissue.
Aurora Kinase A* ; Blotting, Western ; Cytokinesis ; Diabetes Mellitus ; DNA Damage ; Humans ; Mitosis ; Skin*

OBJECTIVETo investigate the cytotoxicity of indium chloride (InCl₃) and its effects on micro-nucleus formation in primary human lymphocytes cultured in vitro.

METHODSThe CCK-8 assay was used to evaluate the cytotoxicity of 24 h exposure to different concentrations of InCl₃(4, 40, 80, 200, 500, and 1 000 µmol/L) in lymphocytes cultured in vitro. The cytokinesis-block method was used to determine the micronucleus level in lymphocytes exposed to different concentrations of InCl₃and the effects of anti-oxidant vitamin C on micronucleus frequency.

RESULTSLymphocytes exposed to InCl₃of no less than 500 µmol/L had significantly lower survival rates than those in the control group (P < 0.05). Lymphocytes exposed to 80 µmol/L InCl₃had a significantly higher micronucleus frequency than those in the control group (P < 0.05). However, there was no further increase in micronucleus frequency of lymphocytes exposed to 200 µmol/L InCl₃. Lymphocytes cultured in whole blood and exposed to 500 or 1000 µmol/L InCl₃had a significantly increased micronucleus frequency than those in the control group (P < 0.001). The increase in micronucleus frequency of lymphocytes induced by indium could be partially antagonized by 20 or 100 µmol/L vitamin C.

CONCLUSIONInCl₃can induce an increase in micronucleus frequency of primary human lymphocytes cultured in vitro, which might be associated with DNA damage induced by oxidative stress.

Cell Nucleus ; metabolism ; Cytokinesis ; DNA Damage ; Humans ; In Vitro Techniques ; Indium ; toxicity ; Lymphocytes ; drug effects ; Oxidative Stress

As the basis of cell proliferation, cytokinesis involves the division of the cytoplasm and the plasma membrane into two. In this paper a few models on the active deformation mechanism during cytokinesis process are presented. Discussions are made onvarious models, conclusions, differences between the numerical results and the corresponding experimental results.
Animals ; Biomechanical Phenomena ; Cell Proliferation ; Computer Simulation ; Cytokinesis ; physiology ; Humans ; Models, Biological

Aurora kinase A plays an essential role in mitosis including chromosome separation and cytokinesis. Aberrant expression and activity of Aurora kinase A is associated with numerous malignancies including colorectal cancer followed by poor prognosis. The aim of this study is to determine the inhibitory effects of LDD970, an indirubin derivative, on Aurora kinase A in HT29 colorectal cancer cells. In vitro kinase assay revealed that, LDD970 inhibited levels of activated Aurora kinase A (IC₅₀=0.37 mM). The inhibitory effects of LDD970 on Aurora kinase A, autophosphorylation and phosphorylation of histone H3 (Ser10), were confirmed by immunoblot analysis. Moreover, LDD970 inhibited migration of HT29 cells and upregulated apoptosis-related protein cleaved PARP. In cell viability assay, LDD970 was observed to suppress HT29 cell growth (GI₅₀=4.22 µM). Although further studies are required, results of the present study suggest that LDD970 provide a valuable insight into small molecule indirubin derivative for therapeutic potential in human colorectal cancer.
Aurora Kinase A* ; Cell Survival ; Colorectal Neoplasms* ; Cytokinesis ; Histones ; HT29 Cells ; Humans* ; In Vitro Techniques ; Mitosis ; Phosphorylation ; Phosphotransferases ; Prognosis

PURPOSE: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. MATERIALS AND METHODS: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or 100 microM) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. RESULTS: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at 100 microM of MEF (38% decrease), providing maximal protection against ionizing radiation. CONCLUSION: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.
Cell Death ; Cytokinesis ; DNA Damage ; Healthy Volunteers ; Humans* ; Inflammation ; Lymphocytes* ; Mefenamic Acid* ; Micronucleus Tests ; Radiation, Ionizing ; Radiation-Protective Agents

Cytogenetic and hematological analyses were performed on the peripheral blood lymphocytes (PBLs) obtained from Korean native cattle bred in the vicinity of three nuclear power plants (Wolsong, Uljin and Yeonggwang) and in a control area. The micronucleus (MN) rates for the cattle from the Wolsong, Uljin and Yeonggwang nuclear power plants and for the control area were 9.87 +/- 2.64, 8.90 +/- 3.84, 9.20 +/- 3.68 and 9.60 +/- 3.91 per 1,000 cytokinesis-blocked lymphocytes, respectively. The apparent difference is not statistically significant. The MN frequencies of PBLs from cattle bred in the four areas are within the background variation for this study. The MN frequencies and hematological values were similar regardless of whether the cattle were bred near a nuclear power plant or in the control area.
Animals ; Blood Cell Count/veterinary ; Cattle/*blood ; Cytokinesis ; Hematocrit/veterinary ; Hemoglobins/analysis ; Lymphocytes/cytology/*radiation effects ; Micronucleus Tests/*veterinary ; *Power Plants ; Radioactive Pollutants/pharmacology