摘要：
Hexavalent chromium (Cr(VI)), a commonly used industrial metal, is a well-known mutagen and carcinogen, and occupational exposure can induce a broad spectrum of adverse health effects, including cancers. Although Cr(VI)-induced DNA damage is thought to be the primary mechanism of chromate genotoxicity and mutagenicity, there is an increasing number of reports showing that epigenetic mechanisms of gene regulation might be a central target of Cr(VI) toxicity. Epigenetic changes, such as changes in phosphorylation, altered DNA methylation status, histone acetylation and signaling pathways, have been observed after chromium exposure. Nevertheless, to better demonstrate the roles of epigenetic modifications in Cr(VI)-induced carcinogenesis, more work needs to be carried out. This study is aimed to investigate changes in biotinidase (BTD) and holocarboxylase synthetase (HCS), two major proteins which maintain homeostasis of the newfound epigenetic modification: histone biotinylation, in cells exposed to Cr(VI). The data showed that Cr(VI) decreased BID expression at the transcriptional level in human bronchial epithelial cells (16HBE). In addition, using the epigenetic modifiers, 5-Aza-2'-deoxycytidine (Aza) and Trichostatin A (TSA), we found that modifications of histone acetylation reversed the inhibition of BID, suggesting that Cr(VI) may cause down regulation of BID by modifications of histone acetylation. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
摘要：
以金针菇汁、果冻粉和橘子汁为主要原料,研制了新型的金针菇橘子果冻.采用单因素和正交试验对金针菇汁的制备、金针菇橘子果冻的原料配比及产品的最佳杀菌条件等进行了研究.试验结果表明,金针菇汁的最佳工艺条件为0.1%抗坏血酸和0.01%柠檬酸溶液料液比为1:1,热烫温度90℃,处理时间4min;金针菇橘子果冻最佳工艺配比为橘子汁35%,金针菇汁10%,水42%,白砂糖13%,柠檬酸0.2%.果冻粉1.5%,山梨酸钾0.05%,在此参数下可研制出组织形态、色泽和口感均优良的果冻.最佳杀菌工艺条件为:90℃杀菌5 min.
作者机构：
[Li, Qingjie] Univ Texas Med Branch Galveston, Div Gastroenterol, Dept Internal Med, Galveston, TX 77550 USA.;[Loehr, Christiane V.] Oregon State Univ, Coll Vet Med, Corvallis, OR 97331 USA.;[Dashwood, Roderick H.] Oregon State Univ, Linus Pauling Inst, Corvallis, OR 97331 USA.;[Dashwood, Roderick H.] Oregon State Univ, Dept Environm & Mol Toxicol, Corvallis, OR 97331 USA.;[Luo, Cunhui] Hunan Agr Univ, Coll Food Sci & Technol, Changsha, Hunan, Peoples R China.
通讯机构：
[Li, Qingjie] U;Univ Texas Med Branch Galveston, Div Gastroenterol, Dept Internal Med, Galveston, TX 77550 USA.
关键词：
activator protein-1;activator protein AP-2;GATA4 transcription factor;liver;protein kinase A
摘要：
Aim: Activator protein 2 alpha (AP-2 alpha) belongs to the AP-2 family of transcription factors that are involved in the regulation of cell proliferation, differentiation, apoptosis and carcinogenesis and has been suggested to function as a tumor suppressor in many cancers. However, the physiological role of AP-2 alpha in hepatocytes is unknown. The present study is to characterize the expression and function of AP-2 alpha in the liver of conscience mouse. Methods: Exogenous AP-2 alpha was overexpressed in the mouse liver by in vivo gene delivery and changes in transcription factor expression were identified by using protein-DNA arrays and immunoblotting. Results: Western blotting and protein/DNA arrays showed that AP-2 alpha is expressed in the nuclei of mouse hepatocytes. Overexpression of AP-2 alpha in vivo significantly suppressed transcription factors AP-1, CREB and c-Myc, and markedly increased CBF, c-Myb, NF-1, Pax-5, RXR, Smad3/4, TR(DR-4), USF-1 and GATA. Among all GATA proteins, only GATA-4 level was dramatically elevated and there was a concomitant loss of phospho-GATA-4. Corresponding changes were detected in upstream kinases Akt, GSK-3 beta and PKA, which regulates the phosphorylation status and stability of GATA-4 protein. Conclusions: AP-2 alpha is expressed in mouse hepatocytes and it acts as a master regulator of numerous transcription factors in the liver.
