Author + information
- Joshua R. DeLeon,
- Jorge Mejia Corletto,
- Siham Accacha,
- Iryna Voloshyna,
- Nicolle Siegart,
- Lora Kasselman,
- Mariano Castro Magana and
- Allison Reiss
Background: A significant challenge in the management of type 1 diabetes (T1DM) is the high incidence of atherosclerotic cardiovascular disease (ASCVD). Atherosclerosis begins before the first clinical symptoms, and causal mechanisms are unclear. We have identified a set of genes that provide a robust assessment of cholesterol transport in macrophages that reflect vulnerability to lipid overload. Here, we examine this profile in naïve THP-1 human macrophages exposed to T1DM versus healthy control (HC) plasma. The status of these genes may act as a surrogate for atherosclerosis risk.
Methods: THP-1 macrophages (106/ml) were incubated for 24 h in RPMI media ± 10% plasma from HC and DM patients in triplicate ± anti-RAGE antibody. Plasma used was from 20 poorly controlled T1DM patients (55% male, age 15±2.6 yrs, mean disease duration 7 yrs) and 20 HC. Cholesterol transport protein mRNA was quantified by real-time RT-PCR using specific primers for each gene
Cholesterol efflux and oxidized LDL uptake were measured.
Results: THP-1 macrophages exposed to T1DM plasma displayed downregulation of reverse cholesterol transport proteins 27-hydroxylase, ABCA1 and LXR and increased scavenger receptor (SR) expression. ABCA1 message was lower in macrophages exposed to T1DM plasma (1.108±0.8U) vs. HC plasma (1.624±0.6U) (p<0.05). 27-hydroxylase was down-regulated to 1.94±0.9U in T1DM plasma vs. 3.4±2.9U in HC plasma (P<0.01). LOX-1 and SR-A1 expression were significantly upregulated in T1DM plasma. Gene expression analysis was confirmed by immunoblot. Cholesterol efflux to medium was 7± 2% lower in T1DM plasma vs. HC plasma (69% vs. 76%). Inactivation of RAGE with anti-RAGE antibody in the presence of T1DM plasma increased ABCA1 by 20% while decreasing both CD36 and LOX1. The 27-hydroxylase enzyme message and cellular lipid balance were not restored by anti-RAGE.
Conclusions: Plasma from subjects with T1DM inhibits cholesterol efflux proteins and suppresses intracellular cholesterol processing in macrophages. T1DM plasma effects are not fully explained by AGE/RAGE abnormalities. Better understanding of T1DM-mediated changes in cholesterol transport may lead to new therapeutic targets for prevention.
Poster Hall, Hall C
Saturday, March 18, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Cutting Edge Vascular Medicine
Abstract Category: 38. Vascular Medicine: Basic
Presentation Number: 1205-362
- 2017 American College of Cardiology Foundation