中文摘要：

目的：研究CBR1基因启动子在猪子宫内膜细胞的表达调控机制。创新点：发现CBR1基因启动子在猪子宫内膜受到炎性因子核转录因子kappa B（NF-κB）成员p65调控。p65对该启动子具有正向调节作用,但是对于CBR1基因的表达并不是必需的。方法：通过双荧光素酶报告基因载体确定CBR1基因启动子转录活性区,通过染色质免疫沉淀（Ch IP）技术确定p65能够结合CBR1基因启动子,通过超表达和干扰表达实验证实p65对CBR1基因启动子的调控作用。结论：猪CBR1基因启动子-1640/-647区对于其转录活性是必需的,在-1545/-1531区存在p65的结合位点。p65在猪子宫内膜细胞中促进了CBR1基因mRNA的表达,但是干扰p65则不会造成CBR1基因mRNA表达量下降,推断p65不是CBR1基因表达的必需因素。

英文摘要：

Prostaglandins （PGs） play a critical role in porcine reproduction, of which prostaglandin E2 （PGE2） and prostaglandin F2a （PGF2a） exert antiluteolytic and luteolysis actions, respectively. As a rate-limiting enzyme, carbonyl reductase 1 （CBR1） catalyzes the conversion of PGE2 to PGF2a. A high ratio of PGE2：PGF2a is beneficial to the establishment and maintenance of porcine pregnancy. PG is essential for the establishment of pregnancy which resembles the proinflammatory response and nuclear factor KB （NF-KB） is involved in the process. Bioinformatic analysis has shown that NF-KB is a possible factor bound to two cis-regulatory elements in CBRI promoter. In this study, we cloned the 2997 bp （-2875/＋122） of the promoter, and constructed six 5＇-deleted dual-luciferase reporter recombinant vectors. In endometrial cells, the region of P2 （-16401＋7） exhibited the greatest transcriptional activity at driving luciferase expression, but not significantly different from that of P1 （-2089/＋7）. The activity of P1, P2, and P3 （-1019/＋7） was highly significantly higher than that of others （P〈0.01）, suggesting that two positive regulatory elements were likely present in the regions of -1640/-1019 and -1019/-647. The results also showed that the -1640/ -647 region was indispensable for the promoter. The results of chromatin immunoprecipitation （CHIP） demonstrated that the NF-KB subunit p65 binds to one site around -15451-1531. Using four reference genes, we found that the over-expression of p65 enhanced the expression of CBR1 （P〈0.05） in porcine endometrial epithelial cells, while knockdown of the p65 did not down-regulate the CBRI expression. These results indicated that NF-KB （p65） could bind to the special element of CBR1 gene promoter in porcine endometrial epithelial cells in vitro. The binding site of NF-KB was a positive regulator for the CBR1 gene promoter, but was not necessary for the basic expression.