Chan J S, Chan A H, Nie Z R, Sikstrom R, Lachance S, Hashimoto S, Carrière S
University of Montreal, Maisonneuve-Rosemont Hospital, Research Center, Quebec, Canada.
J Am Soc Nephrol. 1992 Feb;2(8):1360-7. doi: 10.1681/ASN.V281360.
Angiotensinogen (ANG) messenger RNA is expressed in opossum kidney (OK) proximal tubular cells. To examine whether thyroid hormone, L-T3, could stimulate the expression of the ANG gene in OK proximal tubular cells, fusion genes, consisting of various lengths of the 5'-flanking region of the rat angiotensinogen gene linked to a human growth hormone reporter gene, were constructed and introduced into OK cells. As a negative control, they were introduced into a nonkidney cell line, a human choriocarcinoma cell line (JEG-3). The level of the expression of fusion genes in these cells were determined by the level of immunoreactive human growth hormone secreted into the culture medium. The expression of ANG-growth hormone (ANG-GH) fusion genes pOGH (ANG N-1498/+18), pOGH (ANG N-688/+18), pOGH (ANG N-110/+18), pOGH (ANG N-53/+18), and pOGH (ANG N-35/+18) was 226-, 4.5-, 1.0-, 12-, and 2.5-fold higher than promoterless pOGH in the expression of growth hormone activity in OK cells. No significant expression of any of these ANG-GH fusion genes over the promoterless pOGH was observed in JEG-3 cells. The addition of L-T3 stimulates the expression of pOGH (ANG N-1498/+18) in a dose-dependent manner with a maximal and half-maximal effect at 10(-7) M and at 10(-8) to 10(-9) M, respectively. Thyroid hormone (10(-7) M) also stimulates the expression of pOGH (ANG N-688/+18) but not pOGH (ANG N-110/+18), pOGH (ANG N-53/+18), or pOGH (ANG N-35/+18).(ABSTRACT TRUNCATED AT 250 WORDS)
血管紧张素原（ANG）信使核糖核酸在负鼠肾（OK）近端肾小管细胞中表达。为了研究甲状腺激素L-T3是否能刺激OK近端肾小管细胞中ANG基因的表达，构建了由大鼠血管紧张素原基因不同长度的5'侧翼区与人生长激素报告基因相连的融合基因，并将其导入OK细胞。作为阴性对照，将它们导入非肾细胞系，即人绒毛膜癌细胞系（JEG-3）。这些细胞中融合基因的表达水平通过分泌到培养基中的免疫反应性人生长激素水平来确定。ANG-生长激素（ANG-GH）融合基因pOGH（ANG N-1498/+18）、pOGH（ANG N-688/+18）、pOGH（ANG N-110/+18）、pOGH（ANG N-53/+18）和pOGH（ANG N-35/+18）在OK细胞中生长激素活性表达方面比无启动子的pOGH分别高226倍、4.5倍、1.0倍、12倍和2.5倍。在JEG-3细胞中未观察到这些ANG-GH融合基因相对于无启动子的pOGH有任何显著表达。添加L-T3以剂量依赖方式刺激pOGH（ANG N-1498/+18）的表达，分别在10^(-7)M和10^(-8)至10^(-9)M时达到最大和半最大效应。甲状腺激素（10^(-7)M）也刺激pOGH（ANG N-688/+18）的表达，但不刺激pOGH（ANG N-110/+18）、pOGH（ANG N-53/+18）或pOGH（ANG N-35/+18）。（摘要截短于250字）
