Hepatic aberrant glycosylation by N-acetylglucosaminyltransferase V accelerates HDL assembly

In this study, we investigated the effects of aberrant glycosylation by GnT-V on high-density lipoprotein cholesterol (HDL) assembly. We used GnT-V transgenic (Tg) mice and GnT-V Hep3B cell (human hepatoma cell line) transfectants. The study also included 96 patients who underwent medical health check-ups. Total serum cholesterol levels, particularly HDL-cholesterol (HDL-C) levels, were significantly increased in Tg vs. wild-type (WT) mice. Hepatic expression of apolipoprotein AI (ApoAI) and ATP-binding cassette subfamily A member 1 (ABCA1), two important factors in HDL assembly, were higher in Tg mice compared with WT mice. ApoAI and ABCA1 were also significantly elevated in GnT-V transfectants compared with mock-transfected cells. Moreover, ApoAI protein in the cultured media of GnT-V transfectants was significantly increased. Finally, we found a strong correlation between serum GnT-V activity and HDL-C concentration in human subjects. Multivariate logistic analyses demonstrated that GnT-V activity was an independent and significant determinant for serum HDL-C levels even adjusted with age and gender differences. Further analyses represented that serum GnT-V activity had strong correlation especially with the large-size HDL particle concentration. These findings indicate that enhanced hepatic GnT-V activity accelerated HDL assembly and could be a novel mechanism for HDL synthesis.

Source: AJP: Gastrointestinal and Liver Physiology - November 1, 2016 Category: Gastroenterology Authors: Kamada, Y., Kida, S., Hirano, K.-i., Yamaguchi, S., Suzuki, A., Hashimoto, C., Kimura, A., Sato, M., Fujii, H., Sobajima, T., Yamamoto, A., Ebisutani, Y., Takamatsu, S., Shinzaki, S., Yoshida, Y., Yamada, M., Nagasaka, H., Takehara, T., Miyoshi, E. Tags: NUTRIENT SENSING, NUTRITION, AND METABOLISM Source Type: research