Nornicotine impairs endothelial cell-cell adherens junction complexes in EA.hy926 cell line via structural reorganization of F-actin

The aim of the study was to estimate the effect of nornicotine on endothelial EA.hy926 cells in the context of its impact on cell-cell junctions. The objective of the study was to determine the relationship between junctional proteins and F-actin after treating the cells with nornicotine. After 24 h of cell exposure to 0.08, 0.12, and 0.16 ng/mL nornicotine, analysis was performed of cell death, cell migration, ultrastructure, and colocalization of beta-catenin/F-actin and zonula occludens (ZO)-1/F-actin. Our study did not reveal any alterations in EA.hy926 cell line survival following treatment with nornicotine. However, nornicotine exerted disparate effects on cell migration and led to changes in both the ultrastructure and organization of cell-cell junctional complexes and F-actin. Moreover, the cell migration observed in the experiments performed in the present work negatively correlated with the number of Weibel-Palade bodies seen through transmission electron microscopy (TEM). Moreover, the mechanism of cell migration promotion was VEGF-independent, and the decrease in the number of Weibel-Palade bodies resulted from nornicotine-induced F-actin depolymerization. In conclusion, the present study demonstrated that low concentrations of nornicotine do not affect cell survival, but promote cell movement and impair adherens junctions through changes in F-actin organization. Our results indicate for the first time the effect of nornicotine on endothelial EA.hy926 cells and suggest that nornicotine may induce transmigration pathways and, consequently, facilitate the transendothelial migration of monocytes associated with atherosclerosis

The role of exportin 6 in cytoskeletal-mediated cell death and cell adhesion in human non-small-cell lung carcinoma cells following doxorubicin treatment

The actin cytoskeleton plays an important role in various cellular processes. The different forms ofactin (G-actin and F-actin) participate in the organization of nuclear structure and its functions. The structure of the actin cytoskeleton is controlled by proteins involved in the translocation of actin between cytoplasm and the nucleus. In this study, we used siRNA method to investigate the role of exportin 6 in the switching between nuclear and cytoplasmic F-actin pools in H1299 cells treated with no, 1.0 or 2.5 μM doxorubicin. We showed that silencing of exportin 6 expression changed the response of H1299 to doxorubicin. Here, we observed increased population of cells affected by doxorubicin-induced necrotic cell death. Furthermore, fluorescence studies showed that downregulation of exportin 6 exerted profound DOX-induced changes in the F-actin cytoskeleton architecture. The F-actin cytoskeleton was seen in the form of small fibers or aggregates after doxorubicin treatment. Additionally, some cells lost cell adhesion properties. Downregulation of exportin 6 influenced also transcriptional activity of the cells. In cells transfected with nontargeting siRNA, we observed a higher level of 5’-fluorouridine fluorescence than in cells with silenced export in 6 expression. In conclusion, we showed that downregulation of exportin 6 induced necrotic cell death. Moreover, the observed alterations of cell adhesion suggest the key role of cytoplasmic F-actin in maintaining intercellular junctional complexes and/or focal adhesion properties and the importance of the balance between nuclear and cytoplasmic F-actin pools

Actin filament reorganization in HL-60 leukemia cell line after treatment with G-CSF and GM-CSF.

Currently, information regarding the influence of growth factors on the cytoskeleton, including G-CSF and GMCSF, remains limited. In the present study we show alterations in F-actin distribution and cell cycle progression in HL-60 promyelocytic leukemia cells, resulting from treatment with these cytokines in vitro. We found that both agents caused F-actin reorganization. Although multiple potential effects of various growth factors have been described previously, in our experimental conditions, we observed some rather subtle differences between the effects of G-CSF and GM-CSF on studied cells. The presence of these cytokines in the cell environment caused not only increased F-actin labeling in the cytoplasm, but also a weaker intensity of peripheral ring staining in comparison with control cells. In spite of the fact that HL60 cells exposed to G-CSF and GM-CSF contained different F-actin structures such as aggregates and F-actin network, the rate of actin polymerization was not significantly enhanced. Moreover, alterations were mainly related to considerable changes in the relative proportion of these different structures, what might be reflected by specific features of the differentiation process, with regard to the kind of stimulating factor used. Thus, reorganization of F-actin and other results obtained in our experimental conditions, might reflect unique characteristics of the differentiation process in HL-60 cells, involving low apoptosis frequency, the G1 to S phase transition in the cell cycle, as well as possible alternative ways of the cell death

Effect of arsenic trioxide (Trisenox) on actin organization in K-562 erythroleukemia cells.

Actin is one of the cytoskeletal proteins that take part in many cellular processes. The aim of this study was to show the influence of Trisenox (arsenic trioxide), on the cytoplasmic and nuclear F-actin organization. Arsenic trioxide is the proapoptotic factor. Together with increasing doses, it caused the increase in the number of cells undergoing apoptosis. Under arsenic trioxide treatment, cytoplasmic and nuclear F-actin (polymerized form of G-actin) was found reorganized. It was transformed into granulated structures. In cytometer studies fluorescence intensity of cytoplasmic F-actin after ATO treatment decreasing urgently in comparison to control. The obtained results may suggest the involvement of F-actin in apoptosis, especially in chromatin reorganization

Expression of cyclin B1 after induction of senescence and cell death in non-small cell lung carcinoma A549 cells

The purpose of this study was to evaluate the level of mitotic cyclin B1 in the context of senescence and cell death in A549 non-small cell lung carcinoma cells. This was performed through analysis of the cell cycle, the percentage of SA-β-galactosidase-positive, as well as TUNEL-positive cells. Morphological alterations were studied using a transmission electron microscope. Changes in  the intracellular level and the presence of cyclin B1 in the nucleus and cytoplasm areas were detected by flow cytometry and confocal fluorescence microscopy, respectively. In the cells exposed to various concentrations of doxorubicin, different kinds of cell death and senescent phenotype were observed. Alterations in the cell cycle and increased polyploidy may be indicative of mitotic catastrophe execution. Changes in cyclin B1 may also be strictly related to its different regulation at mitotic catastrophe and senescence programs

White Guilt: Race, Gender, Sexuality and Emergent Racisms in the Contemporary United States

White guilt is a culturally and historically contingent emotion rooted in White people's recognition of unearned privileges and collective and/or individual roles in the perpetuation of racism. Situated within the context of neoliberal multiculturalism, this interdisciplinary dissertation investigates contemporary manifestations of White guilt in popular discourse and the lived experiences of young White adults in the United States. As a form of identity-based affect, White guilt may aid in the development of antiracist White people; however, because White guilt retains a focus on the White subject, it may offer limited potential to transform social relationships and systems of inequity. Three interrelated studies compose the methodological work of this project and undertake the task of empirically grounding White guilt so that we may better understand its forms, limits and consequences. The first study interrogates journalists' coverage of three moments of controversy in the early 21st century: Anderson Cooper's "emotional" reporting during the aftermath of Hurricane Katrina, the Don Imus-Rutgers University basketball scandal and Isaiah Washington's firing from Grey's Anatomy after allegedly calling a co-star a "faggot." Reporting on these episodes illustrates how multiculturalism manages and defers racial guilt and shame while simultaneously eliding the intersections of identity that structure experience. The second study is the creation and initial validation of a survey-based measure of White guilt (the Test of White Guilt and Shame or "TOWGAS"), which attempts to reconcile several limitations of extant research on racial affect - namely, the persistent conflation of guilt and shame. The third study centralizes the intersectionality of White people's experiences through in-depth interviews with 10 White college students. A modified grounded theory approach is used to explore how gender, sexuality and race together influence how these White people a) perceive Imus, Washington and Cooper and b) conceptualize their own Whiteness and the feelings associated with racism and inequality. Finally, the concept of "emergent racisms" is posited as a critical, working framework with which to investigate White racial affect. This theoretical approach emphasizes the complex interactions between identity, affect, attitudes and context (i.e., situation) that co-constitute the phenomenology of White guilt and shame

Doxorubicin-induced F-actin reorganization in cofilin-1 (nonmuscle) down-regulated CHO AA8 cells.

The actin cytoskeleton plays an important role in many cellular processes, including cell mortality, mitosis, cytokinesis, intracellular transport, endocytosis and secretion but also is involved in gene transcription. The dynamics of the actin cytoskeleton is controlled by different classes of actin-binding proteins (ABPs) which regulate the polymerization of actin filaments. In this report we used siRNA against cofilin-1 (nonmuscle) to demonstrate the effect of cofilin on the nuclear and cytoplasmic actin pools in CHO AA8 cells after exposition to various concentrations of doxorubicin. The immunofluorescence studies showed doxorubicin dose dependent tendency to formation the multinucleated giant cells, but also the increase of fluorescence intensity of cofilin in nuclei of untransfected cells. Induction of cell death with doxorubicin treatment in untransfected cells revealed both mitotic catastrophe (in both lower and higher doxorubicin doses) and apoptosis (mostly in higher doxorubicin doses), whereas among cofilin-1 down-regulated cells we observed only mitotic catastrophe. The results suggest that cofilin has apoptosis-inducing ability and that mitotic catastrophe is independent from F-actin content in cell nucleus. In this point of view we conclude that different mechanisms of chromatin reorganization are involved in these two processes. Moreover, we suppose that apoptosis and mitotic catastrophe are independent from each other

Postracial Fantasies and the Reproduction of Scientific Racism

The article offers information on depiction of racism in scientific literature, discussing articles written by Rebecca Tuvel and Perez-Rodriguez. Topics discussed include racial classification in medicine; conceptualization of biological race inspired by naive realism or scientism; and impact of bioethicists on racial justice

Analysis of postural stability and body composition of women after unilateral mastectomy

Summary Introduction: The electrical bioimpedance method allows a non-invasive and precise assessment of the content of fat tissue, muscle mass or the amount of fluid in the body depending on the state of health or lifestyle. Changes in anthropometric features may affect postural stability, general physical fitness of women after mastectomy. In addition, changes in the distribution and amount of fat and lean body components may affect the ability to maintain balance. Aim of the study: Analysis of the relationship between postural stability and body composition of women after mastectomy based on posturographic examination. Material and methods: The study involved 40 women after mastectomy aged from 52 to 87 years. Postural Stability Test in static and dynamic mode on the Biodex Balance System platform was used to assess postural stability. The body bioimpedance method (BIA) was used to analyze the body composition. The research tool was the body composition analyzer Tanita MC 780 MA. The research was carried out in the Posturology Laboratory of the Institute of Physiotherapy at the Jan Kochanowski University in Kielce. Results and conclusions: Based on the research, a significant correlation was observed with a negative correlation in the Postural Stability Test, in static mode between fat mass and postural stability indexes. Also significant statistical results with a positive correlation were demonstrated in the same test between the total body water content and the postural stability indexes. Postural Stability Test in dynamic mode showed significant influence of lean and muscle mass in maintaining a stable posture. The standing posture of women after mastectomy was characterized by larger sublimations in the sagittal plane than the frontal plane (A / P> M // L)