Burke P A, Luo M, Zhu J, Yaffe M B, Forse R A
Department of Surgery, Deacones Hospital/Harvard Medical School, Boston, Mass, USA.
Surgery. 1996 Aug;120(2):374-80; discussion 380-1. doi: 10.1016/s0039-6060(96)80312-6.
Transcriptional regulation in the liver plays a critical role in mediating the acute phase response to injury. The molecular mechanisms driving these transcriptional events, however, are poorly defined in vivo. The liver-specific transcription factor hepatocyte nuclear factor (HNF)-1 binds to the 5' upstream region of many acute phase genes. To explore the connection between injury and transcriptional regulatory mechanisms, we investigated the effect of injury on HNF-1 binding activity.
Liver nuclear extracts were prepared from animals after burn or anesthetized sham burn injury. HNF-1 binding activity, affinity, and off rate were assessed by electrophoretic mobility shift analysis.
HNF-1 binding activity decreased by 28% 1 1/2 hours after injury. The dissociation constant for HNF-1 increased from 0.6 nm to 11.8 nm at 1 1/2 hours after burn injury partly because of an increase in off rate for the HNF-1: DNA complex.
Burn injury leads to a significant decrease in HNF-1 binding activity as a result of decreased affinity of HNF-1 for DNA. These injury-induced alterations in binding of a liver-specific transcription factor for its DNA binding site represent a mechanism for rapidly modulating acute phase gene transcription in vivo.
肝脏中的转录调控在介导对损伤的急性期反应中起关键作用。然而，驱动这些转录事件的分子机制在体内尚不清楚。肝脏特异性转录因子肝细胞核因子（HNF）-1与许多急性期基因的5'上游区域结合。为了探究损伤与转录调控机制之间的联系，我们研究了损伤对HNF-1结合活性的影响。
从烧伤或麻醉假烧伤损伤后的动物制备肝核提取物。通过电泳迁移率变动分析评估HNF-1的结合活性、亲和力和解离速率。
损伤后1.5小时，HNF-1结合活性下降了28%。烧伤损伤后1.5小时，HNF-1的解离常数从0.6纳米增加到11.8纳米，部分原因是HNF-1：DNA复合物的解离速率增加。
烧伤损伤导致HNF-1结合活性显著下降，原因是HNF-1对DNA的亲和力降低。这些损伤诱导的肝脏特异性转录因子与其DNA结合位点结合的改变代表了一种在体内快速调节急性期基因转录的机制。
