In vivo investigation of ruminant placenta function and physiology-a review.
In vivo investigation of ruminant placenta function and physiology-a review.
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反刍动物胎盘功能和生理学的体内研究——综述。
DOI：
10.1093/jas/skac045
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发表时间：
2022
影响因子：
3.3
通讯作者：
Anthony,RussellV
中科院分区：
文献类型：
--
作者：
Tanner,AmeliaR;Kennedy,VictoriaC;Lynch,CameronS;Hord,TaylorK;Winger,QuintonA;Rozance,PaulJ;Anthony,RussellV
胎盘有利于向胎儿输送营养物质，清除胎儿体内的废物，对胎儿进行免疫保护，并具有内分泌器官的功能，从而决定了胎儿生长发育的环境。此外，胎盘本身是一个高度代谢的器官，利用来自母体循环的大部分氧气和葡萄糖。因此，最佳的胎盘功能是后代在子宫内达到其遗传潜能所必需的。在反刍动物中，怀孕的绵羊被广泛用于研究妊娠生理学，部分原因是它们能够在母体和胎儿血管内放置留置导管，从而在非应激和非麻醉条件下对血流、营养物质的吸收和利用以及激素分泌进行稳态调查。这种方法适用于正常妊娠和受损妊娠。因此，我们对绵羊怀孕的体内生理的理解是任何其他物种无法比拟的。然而，直到最近，在确定反刍动物胎盘表达的个体基因的特定功能或意义方面存在重大缺陷。为此，我们在绵羊胎盘中开发并使用了体内RNA干扰（RNAi）来检测与妊娠发育相关的基因（prr15和lin28）、胎盘营养转运（slc2a1和slc2a3）和胎盘源性激素（CSH）的功能和相对重要性。慢病毒载体用于生成病毒，该病毒稳定地整合到受感染细胞的基因组中，从而表达短发夹RNA (shRNA)，当在细胞内处理时，与RNA诱导沉默复合体（RISC）结合，导致特定的mRNA降解或翻译阻断。为了完成体内RNAi，第9天孵化并完全膨胀的囊胚被慢病毒感染4至5小时，然后手术转移到同步受体子宫。只有滋养外胚层细胞被复制缺陷病毒感染，内部细胞群保持不变，单个囊胚移植后，我们通常获得约70%的妊娠率。体内RNAi与血液流动和营养摄取、转移和利用的稳态研究相结合，现在可以为修改反刍动物胎盘中表达的特定基因的翻译的生理后果提供新的见解。
The placenta facilitates the transport of nutrients to the fetus, removal of waste products from the fetus, immune protection of the fetus and functions as an endocrine organ, thereby determining the environment for fetal growth and development. Additionally, the placenta is a highly metabolic organ in itself, utilizing a majority of the oxygen and glucose derived from maternal circulation. Consequently, optimal placental function is required for the offspring to reach its genetic potential in utero. Among ruminants, pregnant sheep have been used extensively for investigating pregnancy physiology, in part due to the ability to place indwelling catheters within both maternal and fetal vessels, allowing for steady-state investigation of blood flow, nutrient uptakes and utilization, and hormone secretion, under non-stressed and non-anesthetized conditions. This methodology has been applied to both normal and compromised pregnancies. As such, our understanding of the in vivo physiology of pregnancy in sheep is unrivalled by any other species. However, until recently, a significant deficit existed in determining the specific function or significance of individual genes expressed by the placenta in ruminants. To that end, we developed and have been using in vivo RNA interference (RNAi) within the sheep placenta to examine the function and relative importance of genes involved in conceptus development (PRR15andLIN28), placental nutrient transport (SLC2A1andSLC2A3), and placenta-derived hormones (CSH). A lentiviral vector is used to generate virus that is stably integrated into the infected cell’s genome, thereby expressing a short-hairpin RNA (shRNA), that when processed within the cell, combines with the RNA Induced Silencing Complex (RISC) resulting in specific mRNA degradation or translational blockage. To accomplish in vivo RNAi, day 9 hatched and fully expanded blastocysts are infected with the lentivirus for 4 to 5 h, and then surgically transferred to synchronized recipient uteri. Only the trophectoderm cells are infected by the replication deficient virus, leaving the inner cell mass unaltered, and we often obtain ~70% pregnancy rates following transfer of a single blastocyst. In vivo RNAi coupled with steady-state study of blood flow and nutrient uptake, transfer and utilization can now provide new insight into the physiological consequences of modifying the translation of specific genes expressed within the ruminant placenta.