CREATE TRANSGENIC RABBITS BY MICROINJECTING HUMAN apoA-Ⅱ GENE INTO FERTILIZED EGGS

Objective To create transgenic rabbits by microinjecting human apolipoprotein A-Ⅱ (apoA-Ⅱ) gene into one-cell embryos, to study apoA-Ⅱ gene function on plasma lipoprotein metabolism and atherosclerosis. Methods Superovulation and synchronization of estrus were induced in female Japanese White Rabbits by injecting hormone, then mating with male. After collected the fertilized eggs, the human apoA-Ⅱ gene was microinjected into the male pronucleus of eggs. The injected eggs were transferred into recipient female rabbits. Last, extract DNA from the new borns ear and determine whether the newborns were transgenic by polymerase chain reaction (PCR) or Southern blot analysis. Results A total of 822 embryos with microinjection of human apoAⅡ gene were implanted into 28 recipient rabbits. The number of surviving newborns was 37. 3 transgenic positive surviving founders were found with human apoA-Ⅱ.

Macrophage-derived matrix metalloproteinase-1 enhances aortic aneurysm formation in transgenic rabbits

Increased expression of matrix metalloproteinase-1(MMP-1)has been observed in the lesions of atherosclerosis and aneurysms;however,it is not fully understood whether macrophage-derived MMP-1 affects these diseases.To investigate whether macrophage-derived MMP-1 participates in the development of vascular diseases,we generated transgenic(Tg)rabbits expressing human MMP-1 in the monocyte/macrophage lineage under the control of the human scavenger receptor enhancer/promoter.Tg rabbits exhibited no visible abnormalities throughout their bodies.Western blotting analysis revealed that the amount of MMP-1 proteins in the conditioned media secreted from peritoneal macrophages of Tg rabbits was up to 3-fold higher than that in non-Tg rabbits.For the first experiment,Tg and non-Tg rabbits were fed a cholesterol diet for 16 weeks,and aortic and coronary atherosclerosis were evaluated.The gross lesion area of aortic atherosclerosis in Tg rabbits was not significantly different from that in non-Tg rabbits,but Tg rabbits had marked destruction of the medial elastic lamina of the aortic lesions on microscopic examination.For the second experiment,we generated aortic aneurysms by incubating with elastase.Compared with non-Tg rabbits,Tg rabbits exhibited a significantly greater aortic dilation.Increased macrophage-derived MMP-1 led to increased medial destruction in both aortic atherosclerosis and aneurysms.These results demonstrate that MMP-1 plays a different role in the pathogenesis of atherosclerosis and aneurysms.