BACKGROUND: During the processes of placenta development, the migration of the trophoblast cells (TCs) is most likely affected by blood flow. This study was to examine the effect of flow-induced shear stress on the migration of the human TCs. METHODS: Using a flow chamber technique, steady-state flow shear stress was imposed on early gestation human TCs cultured on glass slides for up to 24h. The imposed shear stress levels in this study were 0, 7.5, 15, and 30dyn/cm(2), respectively. The motility of TCs under study was evaluated by quantitative analysis of the microscopy pictures captured. FINDINGS: The results showed that in the absence of flow, TCs were highly dynamic with constant non-directional positional shifts, but with no net cell migration. Exposure of the cells to shear stresses of 7.5, 15, 30dyn/cm(2) within 24h significantly increased the level of this activity and led to net cell migration in the direction of flow. INTERPRETATION: The results from the in vitro study demonstrated that shear stress regulated trophoblast motility, but did not induce the migration of TCs in the direction against flow stream like in the situation in vivo. Therefore the present study suggests that in vivo TC migration is most likely regulated not only by mechanical stimuli but by biochemical stimuli as well.
BACKGROUND: During the processes of placenta development, the migration of the trophoblast cells (TCs) is most likely affected by blood flow. This study was to examine the effect of flow-induced shear stress on the migration of the humanTCs. METHODS: Using a flow chamber technique, steady-state flow shear stress was imposed on early gestation humanTCs cultured on glass slides for up to 24h. The imposed shear stress levels in this study were 0, 7.5, 15, and 30dyn/cm(2), respectively. The motility of TCs under study was evaluated by quantitative analysis of the microscopy pictures captured. FINDINGS: The results showed that in the absence of flow, TCs were highly dynamic with constant non-directional positional shifts, but with no net cell migration. Exposure of the cells to shear stresses of 7.5, 15, 30dyn/cm(2) within 24h significantly increased the level of this activity and led to net cell migration in the direction of flow. INTERPRETATION: The results from the in vitro study demonstrated that shear stress regulated trophoblast motility, but did not induce the migration of TCs in the direction against flow stream like in the situation in vivo. Therefore the present study suggests that in vivo TC migration is most likely regulated not only by mechanical stimuli but by biochemical stimuli as well.