Role of ubiquitin ligase Ring2 in DNA damage induced by benzoapyrene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the role of ubiquitin ligase Ring2 in the DNA damage induced by benzo[a]pyrene (B[a]P).</p><p><b>METHODS</b>The expression of Ring2 in human bronchial epithelial (16HBE) cells was inhibited by small interfering RNA (siRNA) to obtain siRNA-Ring2 16HBE cells. The siRNA-Ring2 16HBE cells, as well as normal 16HBE cells, were exposed to B[a]P (0, 1, 2, 4, 8, 16, and 32 µmol/L) for 24 h; other siRNA-Ring2 16HBE cells and normal 16HBE cells were exposed to B [a]P (16 µmol/L) for 0, 1, 2, 4, 8, 12, and 24 h. The levels of DNA damage were evaluated by alkaline single cell gel electrophoresis assay.</p><p><b>RESULTS</b>After being treated with siRNA for 36 h, the siRNA-Ring2 16HBE cells showed a 72% decrease in Ring2 expression compared with normal 16HBE cells. The analysis of covariance showed that whether to be treated with siRNA and concentration of B[a]P had impacts on Olive tail moment (OTM) (P = 0.032 and P < 0.001); the adjusted mean of OTM was significantly higher in siRNA-Ring2 16HBE cells than in normal 16HBE cells. Whether to be treated with siRNA and B[a]P exposure time had impacts on OTM (P = 0.031 and P < 0.001); the adjusted mean of OTM was significantly higher in siRNA-Ring2 16HBE cells than in normal 16HBE cells.</p><p><b>CONCLUSION</b>The DNA of 16HBE cells with decreased Ring2 expression has increased susceptibility to B[a]P, which may be due to reduced H2A monoubiquitination following decrease in Ring2 expression.</p>

Clinical significance of protein Z alteration in patients with cardio-cerebral thrombotic diseases / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the alteration of protein Z (PZ) in patients with cardio-cerebral thrombotic diseases, its clinical significance and relations with FX.</p><p><b>METHODS</b>PZ and FX:Ag were measured by ELISA, and plasma FX:C by first stage method. In 170 patients with acute ischemic stroke (AIS), 40 acute myocardial infarction (AMI) and 60 healthy adults as contrast, PZ, FX:C and FX:Ag were measured and compared between incipience and recurrence, different ages and genders.</p><p><b>RESULTS</b>In AIS and AMI groups, PZ levels decreased significantly to (940.02 +/- 229.82) microg/L and (1071.44 +/- 180.52) microg/L, respectively \[the contrast group was (2257.97 +/- 479.76) microg/L, P < 0.001\]. But FX:C and FX:Ag raised to (136.73 +/- 34.93)% and (135.54 +/- 54.39)% in AIS group; and to (139.53 +/- 29.18)%, (129.75 +/- 21.91)% in AMI group, respectively, while in the contrast group they were (94.33 +/- 22.00)% and (77.22 +/- 13.19)% (P < 0.001). In the comparative research between the AIS group, AMI group and the contrast group, PZ level was clearly found to negatively relate to the level of FX:C and FX:Ag (P < 0.001). Meanwhile, PZ level, FX:C and FX:Ag in recur-AIS group and recur-AMI group exhibited significant differences (P < 0.05) from those in the primary AIS and AMI groups, suggesting that the decrease of PZ levels reflected the pathological process of the disease. In addition, PZ level gradually decreased with the increase of age (P < 0.05), while FX:C and FX:Ag had no relations with age (P > 0.05). No correlation was found in sex with PZ level, FX:C, FX:Ag (P > 0.05).</p><p><b>CONCLUSION</b>PZ level was significantly decreased in AIS and AMI patients and was negatively related to FX:C and FX:Ag. The mechanism leading to FX increase may partially related with the decreased of PZ. PZ level was different in the primary and recurrent disease and was gradually decreased with the increase of age. Lack of PZ might be a etiological factor of cardio-cerebral thrombotic diseases.</p>