Phillippe Mark, Bradley Diana F, Ji Huiling, Oppenheimer Karen H, Chien Edward K
Department of Obstetrics and Gynecology, University of Vermont College of Medicine, Burlington, Vermont 05403, USA.
J Soc Gynecol Investig. 2006 Oct;13(7):497-501. doi: 10.1016/j.jsgi.2006.06.002. Epub 2006 Sep 15.
Phospholipid scramblases (PLSCRs), a family of novel membrane proteins, facilitate the translocation of aminophospholipids from the inner to the exterior leaf of the cell membrane. Four isoforms of PLSCR (PLSCR1-4) have been reported in mouse and human. The studies described in this report sought to characterize the uterine expression of the PLSCR isoforms in the near-term pregnant rat.
Uterine tissue was obtained from timed-pregnant Sprague-Dawley rats. Total RNA was isolated, treated with DNase, and used in qualitative and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) studies utilizing PLCSR isoform PCR primers. A rat spleen cDNA bacteriophage library was used as a template for PCR-based sequencing to determine the cDNA and translated amino acid sequences for the PLSCR3 and PLSCR4 homologs expressed in rats. The 5' and 3' untranslated regions were obtained using 5' and 3' Rapid Amplification of cDNA Ends (RACE) techniques.
RT-PCR studies confirmed expression of PLSCR3 and PLSCR4 in the endometrial and myometrial layers of the pregnant rat uterus; in contrast, PLSCR1 and PLSCR2 were not found in uterine tissues. The cDNA sequence for the rat PLSCR3 homolog was found to be 1642 nucleotides, having 92% identity with mouse and 80% with human PLSCR3. The rat PLSCR4 homolog has a cDNA sequence of 1879 nucleotides, having an 89% identity with mouse and 72% identity with human PLSCR4 homologs.
The intrauterine expression of PLSCR3 and PLSCR4 provides a dynamic mechanism by which aminophospholipid translocation can be regulated, thereby modulating the activity of various membrane proteins that are involved in inflammation and coagulation-related events.
磷脂翻转酶（PLSCRs）是一类新型膜蛋白家族，可促进氨基磷脂从细胞膜内叶向外侧叶的转运。在小鼠和人类中已报道了PLSCR的四种亚型（PLSCR1 - 4）。本报告中描述的研究旨在表征近足月妊娠大鼠子宫中PLSCR亚型的表达情况。
从定时妊娠的Sprague - Dawley大鼠获取子宫组织。分离总RNA，用DNase处理，并用于利用PLCSR亚型PCR引物的定性和定量逆转录聚合酶链反应（RT - PCR）研究。使用大鼠脾脏cDNA噬菌体文库作为基于PCR测序的模板，以确定大鼠中表达的PLSCR3和PLSCR4同源物的cDNA和翻译后的氨基酸序列。使用5'和3' cDNA末端快速扩增（RACE）技术获得5'和3'非翻译区。
RT - PCR研究证实PLSCR3和PLSCR4在妊娠大鼠子宫的子宫内膜和肌层中表达；相比之下，在子宫组织中未发现PLSCR1和PLSCR2。发现大鼠PLSCR3同源物的cDNA序列为1642个核苷酸，与小鼠的同源性为92％，与人类PLSCR3的同源性为80％。大鼠PLSCR4同源物的cDNA序列为1879个核苷酸，与小鼠的同源性为89％，与人类PLSCR4同源物的同源性为72％。
PLSCR3和PLSCR4在子宫内的表达提供了一种动态机制，通过该机制可以调节氨基磷脂的转运，从而调节参与炎症和凝血相关事件的各种膜蛋白的活性。
