Overexpression of PID1 reduces high density lipoprotein level and functionality in swine

Phosphotyrosine interaction domain 1 (PID1), a protein with a phosphotyrosine-binding (PTB) domain, interacts with the lipoprotein receptor-related protein 1 (LRP1) to reduce the insulin sensitivity of adipocyte. Considering the role of LRP1 in lipid metabolism, we investigated the effect of PID1 on the content and biological activities of serum lipoproteins in pigs. PID1-transgenic pigs were genetated by sperm and magnetic nanoparticles-mediated method. The levels of PID1 in PID1-transgenic pig's liver were higher than that in the wild-type pig's liver. We found that serum levels of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) were significantly reduced in PID1-transgenic pigs. On the other hand, PID1-transgenic pigs displayed increased non-HDL-C levels. Serum levels of total cholesterol and triglycerides were comparable between the PID1-transgenic and the wild-type pigs. Further, the HDL isolated from PID1-transgenic pigs showed a significant reduction in cholesterol efflux ability. In addition, serum superoxide dismutase activity of PID1-transgenic pigs was also obviously lowered compared with that of wild type pigs. In conclusion, these results suggest that PID1 might be able to adjust HDL-C levels in serum and HDL cholesterol efflux ability.