The Effect Of Integrin β1 On Adhesion Of Human Villous Trophoblast Cells

During the development of human placenta, invasion and migration of trophoblast cells (TCs) within the uterine vasculature is an essential process for the remodeling of the uterine vasculature. In vivo, the processes of cell migration are that TCs firstly invade into the capillary vessels, then migrate within uterine vasculature, and eventually reside within the spiral arteries. This indicates that the direction of TC migration within the uterine vasculature is against the blood stream. In order to understand the physiological roles of TCs in the pregnancy process and the mechanism of TC invasion into the uterine vasculature, many progress were made. However, little has been known about the hemodynamic mechanism of TC migration against the blood stream. Therefore, the correlation between integrinβ1 and the migratory behaviors of TCs was analyzed on the adhesion molecule level in order to understand the mechanism of TC invasion against the blood stream. The main works and results,conclusions in this paper are as follow:First, a simple and stable protocol for human trophoblast cell culture was established. The results revealed that the population of isolated human TCs were significantly augmented using the digesting method of trypsin and DNase at 37℃. The purification of TCs was carried out by serial progress, and cytokeratin positive of TCs was greater than 95%. Configuration of the TCs isolated and cultured were singularity and the growth was stable with stronger viability.Then, using a micropipette aspiration technique, the adhesive mechanical properties of TCs were measured. The results revealed that the adhesion forces of TCs to type I rat collagen increased with increasing concentration of collagen I. When contacted with HUVECs, the adhesion force of TCs was significantly enhanced. Moreover, from the point of view of adhesion molecules, the adhesive mechanical properties of TCs to collagen I was compared with those of TCs to HUVECs. The results suggested that trophoblast integrinβ1 played an important role in the adhesion of TCs.Finally, integrinβ1 expression of TCs on the tissue sections and the isolated TCs were analyzed. The results demonstrated that migratory TCs was accompanied by higher integrinβ1 expression when compared to the non-migratory TCs. Shear stress up-regulated the integrinβ1 expression of TCs, and expression of integrinβ1 of TCs significantly changed with time. TCs co-cultured with endothelial cells increased the expression of integrinβ1 when compared with the TCs cultured alone, suggesting again that trophoblast integrinβ1 played a role in the adhesion and migration of TCs.The experimental results in this paper may provide quantitative referenced gist in opening out relations between mechanical properties of TCs and its growth, invasion, migration; finding out the mechanism of all-sidely TC invasion into the uterine vasculature.