Galectin-8 Contributes to Human Trophoblast Cell Invasion

Galectins are a class of lectins that are extensively expressed in all organisms. Galectins are involved in a range of functions, including early development, tissue regeneration, cancer and inflammation. It has been shown that galectin-8 is expressed in the villous and extravillous trophoblast (EVT) cells of the human placenta; however, its physiological role in pregnancy establishment has not been elucidated. Taking these factors into account, we investigated the functional role of galectin-8 in HTR-8/SVneo cells-a human EVT cell line-and human primary cytotrophoblast cells isolated from a first-trimester placenta. We analyzed the effects of recombinant human galectin-8 (rh galectin-8) on the adhesion, migration and invasion of HTR-8/SVneo cells. We used qPCR, cell-based ELISA (cELISA) and gelatin zymography to study the effects of galectin-8 on mediators of these processes, such as integrin subunits alpha-1 and beta-1 and matrix metalloproteinases (MMPs)-2 and -9, on the mRNA and protein levels. Further, we studied the effects of galectin-8 on primary cytotrophoblast cells' invasion. Galectin-8 stimulated the adhesion, migration and invasion of HTR-8/SVneo cells, as well as the invasion of primary cytotrophoblasts. In addition, the MMP-2 and -9 levels were increased, while the expression of integrins alpha-1 and beta-1 was not affected. Galectin-8 has the ability to positively affect EVTs' invasion, so it can be considered a significant factor in the trophoblast cell invasion process.