[Effect of Acupuncture on c-fos Expression in the Lung Tissue of Bronchial Asthmatic Rats].

Objective To observe the effect of acupuncture on c-fos expression in the lung tissue of asthmatic rats. Methods Totally 70 SPF grade male SD rats were randomly divided into 7 groups, i.e., the blank group (A) , the asthma model group (B) , the blank control group (C) , the asthma-model acupuncture control group (D) , the asthma model acupuncture group ( E) , the asthma model sham-acu- puncture group (F) , the blank acupuncture group (G) , 10 rats in each group. Corresponding interventions were performed to each group. The protein expression of c-fos in lung tissue of rats was detected u- sing immunohistochemistry and Western blot respectively. Results Immunohistochemistry showed negative expression of c-fos protein in Group A, C, G, and E, and weakly positive in Group B, D, and F. Results of Western blot showed the protein expression of c-fos was higher in Group B than in Group A and E (P <0. 01). The protein expression of c-fos was lower in Group E than in Group D and F (P <0. 05, P < 0. 01). Conclusion Acupuncture could reduce the protein expression of c-fos in lung tissue, thus attenu- ating inflammation reaction.

Calmodulin regulates the post-anaphase reposition of centrioles during cytokinesis.

A transient postanaphase repositioning of the centriole is found to control the completion of cytokinesis. Using a green fluorescent protein-calmodulin fusion protein as a living cell probe, we have previously found that calmodulin is associated with the initiation and progression of cytokinesis. In this study, we further studied the effect of calmodulin on the repositioning of the centriole and subsequent cell cycle progression. When activity of calmodulin is inhibited, the regression of the centriole from the intercellular bridge to the cell center is blocked, and thus the completion of cell division is repressed and two daughter cells are linked by longer cell bridge in perturbed cells. W7 treatment during cytokinesis also results in unfinished cytokinesis and stopped G1 phase. These results suggest that calmodulin activity is required for centriole repositioning and can affect the completion of cytokinesis and cell cycle progression.

The association of calmodulin with central spindle regulates the initiation of cytokinesis in HeLa cells.

Calmodulin is a major cytoplasmic calcium receptor that performs multiple functions in the cell including cytokinesis. Central spindle appears between separating chromatin masses after metaphase-anaphase transition. The interaction of microtubules from central spindle with cell cortex regulates the cleavage furrow formation. In this paper, we use green fluorescence protein (GFP)-tagged calmodulin as a living cell probe to examine the detailed dynamic redistribution and co-localization of calmodulin with central spindle during cytokinesis and the function of this distribution pattern in a tripolar HeLa cell model. We found that calmodulin is associated with spindle microtubules during mitosis and begins to aggregate with central spindle after anaphase initiation. The absence of either central spindle or central spindle-distributed calmodulin is correlated with the defect in the formation of cleavage furrow, where contractile ring-distributed CaM is also extinct. Further analysis found that both the assembly of central spindle and the formation of cleavage furrow are affected by the W7 treatment. The microtubule density of central spindle was decreased after the treatment. Only less than 10% of the synchronized cells enter cytokinesis when treated with 25 microM W7, and the completion time of furrow regression is also delayed from 10 min to at least 40 min. It is suggested that calmodulin plays a significant role in cytokinesis including furrow formation and regression, The understanding of the interaction between calmodulin and microtubules may give us insight into the mechanism through which calmodulin regulates cytokinesis.

[The distribution of calmodulin with midbody and its involvement in cytokinesis regulation].

Calmodulin (CaM) is a major cytoplasmic Ca2+ receptor and performs a multiplicity of functions in the cell. By using GFP-CaM fusion protein, we have studied the detailed dynamic redistribution of CaM during cytokinesis in HeLa cells. CaM associates with midbody in late cytokinesis phase. When the cells were treated with Ca2+/CaM inhibitor W7, the dissolving of the midbody was delayed. Moreover, we have found that gamma-tubulin colocalized with CaM at the midbody during cytokinesis. W7 treatment could affect the dissociation of gamma-tubulin from midbody. These results suggest that CaM may involve in the regulation of midbody microtubules disassembly and may thus affect the completion of cytokinesis.