Renfa Liu

BME PhD Thesis Defense Presentation

Date: Thursday, October 31(Atlanta) / Friday, November 1 (Beijing)

Time: 9:00 PM (Atlanta) / 9:00 AM (Beijing)

Location: No.1 Building of COE, Room 212, PKU.

(Bluejeans, https://bluejeans.com/320822111)

Committee members:

Zhifei Dai (Advisor, PKU-BME)

Hanjoong Jo (Co-Advisor, GT-BME)

Brooks Lindsey (GT-BME)

Jinrui Wang (PKU-Third Hospital)

Xiaolong Liang (PKU- Third Hospital)

Ultrasound-guided transgene expression of KLK10 to inhibit atherosclerosis

Atherosclerosis is the leading causes of death worldwide. Atherosclerotic plaques preferentially develop in regions exposed to disturbed flow. Vascular endothelial cells respond to blood flow through mechanosensors, which transduce the shear stress associated with flow into cell signaling events and ultimately result in proatherogenic responses. Our previous studies show that KLK10 is an important atheroprotective gene, which is downregulated by disturbed flow. Therefore, transgene expression of KLK10 gene in vivo to normalize the dysfunctional endothelial cells is a promising therapy. However, targeted gene delivery to vascular endothelial cells remains a hard task.

Ultrasound as a cheap, noninvasive, non-ionizing and real-time imaging technique is an ideal tool for progress monitoring of atherosclerosis. At high power, ultrasound combined with microbubbles has been demonstrated to facilitate gene delivery. In this research, we established a new technique for image-guided targeted gene delivery to mouse artery utilizing the synergistic effect between ultrasound and microbubbles. With color Doppler imaging, the anatomical structure of artery can be visualized and the area of interest can be selected so that ultrasound only irradiate the selected area. After microbubbles injection, the ultrasound can destroy the microbubbles only in the selected areas, resulting increased permeability of the artery. Following system administration, adeno-associated virus (AAV) gene vector can preferentially accumulate in the ultrasound-treated area, resulting in highly enhanced transgene expression. Our results show that this technique can be used for targeted gene delivery to carotid artery, abdominal aorta, and femoral artery. In the acute atherosclerotic model established by partial carotid ligation surgery, KLK10 expression in the left common carotid artery can be recovered with this new method of gene delivery and the development of atherosclerosis can be inhibited. We believe the technique established here may find its broad applications in fundamental studies and clinical translation in respect to artery diseases, such as atherosclerosis, AAA, and PAD.