Role of LIN28A in Mouse and Human Trophoblast Cell Differentiation.

Biology of reproduction

PubMedID: 24006280

Seabrook JL, Cantlon JD, Cooney AJ, McWhorter EE, Fromme BA, Bouma GJ, Anthony RV, Winger QA. Role of LIN28A in Mouse and Human Trophoblast Cell Differentiation. Biol Reprod. 2013;.
Proper regulation of trophoblast proliferation, differentiation and function are critical for placenta development and function. The RNA-binding protein, LIN28A, has been well characterized as a potent regulator of differentiation in embryonic stem cells, however little is known about the function of LIN28A in the placenta. We assessed LIN28A in vitro using mouse trophoblast stem cells (mTS) and human trophoblast cells (ACH-3P). We observed that LIN28A decreased and let-7 miRNA increased when mTS were induced to differentiate into mTGCs upon the removal of FGF4, heparin and conditioned medium. Similarly, we observed that LIN28A decreased in ACH-3P cells induced to syncytialize with forskolin treatment. To assess LIN28A in vivo we examined embryonic day 11.5 mouse placenta and observed abundant LIN28A in the chorioallantoic interface and labyrinth layer, with little LIN28A staining in spongiotrophoblast or differentiated trophoblast giant cells (mTGC). Additionally, shRNA-mediated LIN28A knockdown in ACH-3P cells resulted in increased spontaneous syncytialization, and increased levels of syncytiotrophoblast markers: hCG, LGALS13 and ERVW-1 mRNA. Additionally, targeted degradation of LIN28A mRNA increased responsiveness to forskolin-induced differentiation. In contrast, targeted degradation of Lin28a mRNA in mTS cells did not alter cell phenotype when maintained under proliferative culture conditions. Together these data establish that LIN28A has a functional role in regulating trophoblast differentiation and function, and that loss of LIN28A in human trophoblast is sufficient to induce differentiation, but does not induce differentiation in the mouse.