BACKGROUND: Studies have shown that human umbilical vein endothelial cells participate in vascular structural disorders and dysfunction due to a series of causes, which may become a new target for the treatment of related diseases.
OBJECTIVE: To investigate the protective effect and mechanism of low-intensity pulsed ultrasound on the high glucose-induced injury to human umbilical vein endothelial cells.
METHODS: Human umbilical vein endothelial cells were randomly divided into normal control group, high glucose group and 30, 60 and 90 mW/cm2 low-intensity pulsed ultrasound groups. For the high glucose group and three low-intensity pulsed ultrasound groups, the high-glucose stimulation with 25 mmol/L glucose was given. Additionally, the cells in the three low-intensity pulsed ultrasound groups received 30, 60, and 90 mW/cm2 low-intensity pulsed ultrasounds, 20 minutes per day for 7 continuous days, respectively. MTT was used to detect cell activity and flow cytometry was used to detect cell apoptosis in each experimental group. Colorimetry was used to detect Caspase-3 and -9 activities in the human umbilical vein endothelial cells. Spectrophotometry was used to detect malonaldehyde content, superoxide dismutase activity, catalase activity, and glutathione peroxidase activity. Expression of JNK in the cells was observed by western blot and RT-PCR.
RESULTS AND CONCLUSION: After high glucose treatment, the viability of human umbilical vein endothelial cells was significantly lowered; the apoptosis rate, malonaldehyde content and activities of Caspase 3 and 9 were significantly increased (P < 0.01); the activities of superoxide dismutase, catalase and glutathione peroxidase significantly decreased (P < 0.01); and the JNK expression level was up-regulated (P < 0.01). Compared with the high glucose group, the cell viability of the low-intensity pulsed ultrasound groups (30, 60,90 mW/cm2 subgroups) was increased (P < 0.01), and the apoptosis rate, malonaldehyde content, and Caspase 3, 9 activities were decreased (P < 0.01), superoxide dismutase, catalase and glutathione peroxidase activities were increased (P < 0.01), and JNK expression level was down-regulated (P < 0.01). The above changes were most obvious when the irradiation intensity was 90 mW/cm2. In conclusion, low-intensity pulsed ultrasound can inhibit the high glucose-induced apoptosis of human umbilical vein endothelial cells by increasing the antioxidant capacity and regulating the JNK signaling pathway, further inhibiting the high glucose-induced injury to the human umbilical vein endothelial cells. The low-intensity pulsed ultrasound at 90 mW/cm2 can achieve the best outcomes.