Expression of ApoE Attenuates Differentiation of the White Adipose Tissue from ApoE-Knockout Diabetic Mice

Abstract

Background: What and how the adipose-derived ApoE regulates biological features and lipid metabolism in the diabetic adipose tissue remain little known. Methods: ApoE-/- and wild type mice were randomly divided into 4 groups: ApoE-/- group (EKO); streptozotocin (STZ)-induced diabetic apoE-/- group (EKODM); wild type group(WT); and STZ-induced diabetic wild type group (WTDM). Epididymal white adipose tissue isolated from part EKODM mice were transplanted into backs of WT mice and WTDM mice respectively, all recipient mice were fed with standard chow for 8 weeks. Vital signs, fasting plasma glucose, serum triglycerides(TG) and total cholesterol(TC) were measured every 4 weeks. After sacrifice, epididymal and transplanted white adipose tissue were harvested from all recipient mice. Histomorphologic alterations of adipose tissue were observed. Lipid ingredients of adipose tissue were extracted and measured. Genes expression of ApoE,lipoprotein lipase (LPL),hormone sensitive lipase(HSL),fatty acid synthase(FAS) in adipose tissue were detected by the RT-PCR. Results: 1) After transplantation, the donor adipocytes size from EKODM→WT and EKODM→WTDM mice were both larger than that of EKODM itself. 2) Adipose TG contents of EKO and WTDM group were both lower than that of WT group, while EKODM→WT transplantation increased TG content but kept TC content unchanged compared with the EKODM→WTDM. 3) Adipose tissues of EKODM→WT and EKODM→WTDM group both significantly expressed ApoE. 4) Gene expressions of HSL, LPL, and FAS in donor adipose tissues from either EKODM→WT and EKODM→WTDM group were all significantly increased if compared with the EKODM group. Conclusions: Adipose-derived ApoE may facilitate adipocyte differentiation in mice, even in a diabetic state. Disclosure J. Ran: None. X. Pan: None. R. Zhang: None. P. Zhu: None. R. Tan: None. Y. Liu: None.