ABSTRACT
Objective To study the reactive oxygen level and the expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax after treatment of DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-Aza-2'-dc) and paraquat in V79 cells.Methods Cultured V79 cells were divided into 5-Aza-2'-dc treatment group (group A),paraquat treatment group (group B),5-Aza-2'-dc and paraquat treatment group (group C,V79 cells were pretreated with 5-Aza-2'-dc for 12h followed by exposure to paraquat for 12h) and control group (group D).Reactive oxygen level in V79 cells was measured by DCFH-DA flow cytometry and expression of Bcl-2 and Bax was detected by Western blot.Results Reactive oxygen levels and expression levels of Bcl-2 and Bax in V79 cells were significantly different (P＜0.05) in 5-Aza-2'-dc and paraquat treatment group (group C),compared with 5-Aza-2'-dc treatment group (group A),paraquat treatment group (group B) and control group (group D).Expression levels of Bcl-2 and the ratio of Bcl-2 and Bax were lower while reactive oxygen levels and expression levels of Bax were higher in group C than in groups A,B and D.Conclusion 5-Aza-2'-dc regulates DNA methylation by the imbalancing the reactive oxygen metabolism and apoptosis,thus up-regulating the toxic effect of paraquat on V79 cells.
ABSTRACT
Objective To study the effect of DNA methylation regulation on the toxic effect of paraquat on the sensitized V79 cells t pretreated with 5-aza-2'-deoxycytidine.Methods V79 cells were treated by 5-aza-2'-deoxycytidine (5-Aza-2'-dc) for 12h,which is a DNA methylation inhibitor,and then treated with paraquat for 12h.The morphological changes of V79 cells were observed by microscopy and the cell viability was determined by MTT assay and trypan blue staining method.Results Microscopic examination showed that the combination of 5-Aza-2'-dc and paraquat had stronger effect in inhibiting the growth of V79 cells(the cells became smaller and poorer adhensive ability) than single 5-Aza-2'-dc or paraquat.MTT assay showed that cell viability in the combination group (54.47 ± 3.04) ％ was significantly lower than the 5-Aza-2'-dc group (95.52 ± 0.90) ％ and paraquat group (89.68 ± 4.26) ％ (P＜0.05).Trypan blue staining assay showed that the death rate of ceils in the combination group (53.58 ± 1.57) ％ was significantly higher than the 5-Aza-2'-dc group (7.44 ± 2.31) ％ and paraquat group (12.90 ± 1.21) ％ (P＜0.05) Conclusion 5-Aza-2'-dc promotes V79 cells damage caused by paraquat.
ABSTRACT
Objective To investigate the pathological characteristics of lymph nodes,liver and bone morrow in adult-onset still' s disease (AOSD).Methods The clinical data of three AOSD patients were collected and their biopsy of enlarged lymph nodes,liver and bone marrow were analyzed by histology and immunohistochemistry.Results In AOSD lymphadenopathy,there were high lymph node hyperplasia,partial architecture damage and an intense paracortical hyperplasia along with diffused infiltration of large immunoblasts,activated lymphocytes,Langerhans cells,histocytes,neutrophils and chronic inflammatory cells.Bone marrow biopsy showed a significant increase in the proportion of granulocytes and erythrocytes,with apparently increased segmented neutrophils.Hepatic biopsy showed hepatocellular spotty necrosis.Meanwhile,there was some infiltration of lymphocytes and neutrophils in the periportal fibrosis area.Immunohistochemical staining showed CD21 expression in lymphoid follicle remnants and B cell markers with few T markers in most of immunoblasts.Conclusion The pathological characterizations of lymph nodes,liver and bone marrow provide important clues to the diagnosis of AOSD as well as its differential diagnosis.