High impact information on APOE

• Synthesis and secretion of apolipoprotein E occur independently of synthesis and secretion of apolipoprotein B-containing lipoproteins in HepG2 cells [1].
• Before the time point at which dominant follicles can be distinguished by virtue of their deviation in size and growth rate, transcripts for inhibin beta A, apolipoprotein E receptor 2, and p450 aromatase were elevated specifically in the one to three largest follicles [2].
• This study describes the characterization and isolation of a high-affinity-binding protein for apolipoprotein E-free HDL from the plasma-membrane fraction of bovine corpora lutea [3].
• Cloning and sequencing of bovine apolipoprotein E complementary DNA and molecular evolution of apolipoproteins E, C-I, and C-II [4].
• The livers of both baboons and rhesus monkeys fed a high fat, high cholesterol diet secreted very low density lipoproteins (VLDL) that were enriched in cholesteryl ester and apoe as compared to VLDL secreted by the livers of chow-fed animals [5].

Biological context of APOE

• By means of cosmid mapping, we further demonstrate that the APOE-APOC1-APOC2 gene cluster is evolutionary conserved in cattle [6].
• Liver biopsies were performed on d -35, 3, and 35 relative to day of calving, and gene expression of ApoB(100), ApoE, and MTP were determined on liver tissue [7].
• Evolutionary conservation of the apolipoprotein E-C1-C2 gene cluster on bovine chromosome 18q24 [6].
• Release of Apo E was observed only on Day 3 of the estrous cycle [8].

Anatomical context of APOE

• Apolipoprotein E has been demonstrated to be a major secretory protein of human monocyte macrophages [9].
• Microsequencing of bovine cerebrospinal fluid apolipoproteins: identification of bovine apolipoprotein E [10].
• In Peyer's patches, both BSA-Ag and SpAb were more actively absorbed and transcytosed toward the dome area by the ApoEp of the dome apex than by the M cells [11].
• These findings suggest that sensitized soluble luminal antigens are taken up by ApoEp in the small intestine and are finally persorbed into the peripheral blood [11].
• In the small and large intestines, both the BSA antigen (BSA-Ag) and its specific antibody (SpAb) were absorbed by the epithelial cells at the late apoptotic stage (ApoEp), and were subsequently transcytosed by membranes of the small vesicles [11].

Associations of APOE with chemical compounds

• Within a species, a positive relationship may exist between HDL apolipoprotein E content and importance of HDL cholesterol as a precursor for steroidogenesis [12].
• A "HDL pathway" exists for uptake of sterol from HDL void of apolipoprotein E [12].

Physical interactions of APOE

• Inhibition of lipoprotein lipase by the receptor-binding domain of apolipoprotein E [13].

Other interactions of APOE

• To our knowledge, no studies have simultaneously measured ApoB(100), ApoE, and MTP mRNA in periparturient dairy cows [7].
• This study demonstrates for the first time that the corpus luteum synthesizes Apo E and Apo A-I and expresses their respective mRNAs [8].

Analytical, diagnostic and therapeutic context of APOE

• The identification of the immunoreactive material as apolipoprotein E was confirmed by labelling the cells with [35S]methionine, followed by fractionation of the 35S-labelled secretory products by anti-apolipoprotein E affinity chromatography and SDS-gel electrophoresis [9].
• No apolipoprotein B mass was detected with a specific radioimmunoassay capable of detecting 10 ng apolipoprotein B. No apolipoproteins A-I, C-II or C-III mass was detected, even though the radioimmunoassays for these apolipoproteins were as sensitive as that for apolipoprotein E (detection limit of 0.2 ng) [9].
• Inhibin beta A, apolipoprotein E receptor 2, MAPK kinase kinase 5 (ask1), and carboxypeptidase D were isolated and verified to be reliable markers for dominant follicles using real-time RT-PCR [2].
• Elution profiles from both composites showed a peak that did not bind to the column that contained HDL devoid of apolipoprotein-E as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining and immunoblot analysis [14].

References