Duong M, Uno K, Nankivell V, Bursill C, Nicholls SJ. Induction of obesity impairs reverse cholesterol transport in ob/ob mice.
PLoS One 2018;
13:e0202102. [PMID:
30216355 PMCID:
PMC6138368 DOI:
10.1371/journal.pone.0202102]
[Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 07/27/2018] [Indexed: 11/25/2022] Open
Abstract
Objectives
Obesity is an independent risk factor for cardiovascular disease. Reverse cholesterol transport (RCT) is an important cardioprotective mechanism. This study aimed to investigate RCT changes in a murine model of obesity.
Methods
Ob/ob and control mice were injected with [3H]-cholesterol-labelled macrophages and cholesterol accumulation quantified after 48 h. Ex vivo, cholesterol efflux and uptake were determined in hepatic and adipose tissues.
Results
Ob/ob mice had more labelled cholesterol in their plasma (86%, p<0.001), suggesting impaired RCT. SR-BI-mediated cholesterol efflux was elevated from ob/ob mice (serum, 33%; apoB-depleted plasma, 14%, p<0.01) and HDL-c were also higher (60%, p<0.01). Ex vivo it was found that cholesterol uptake was significantly lower into the livers and adipose tissue of ob/ob mice, compared to non-obese wildtype controls. Furthermore, ex vivo cholesterol efflux was reduced in ob/ob liver and adipose tissue towards apoA-I and HDL. Consistent with this, protein levels of SR-BI and ABCG1 were significantly lower in ob/ob hepatic and adipose tissue than in wildtype mice. Finally, labelled cholesterol concentrations were lower in ob/ob bile (67%, p<0.01) and faeces (76%, p<0.0001).
Conclusion
Obesity causes impairment in RCT due to reduced plasma cholesterol uptake and efflux by hepatocytes and adipocytes. A reduction in the capacity for plasma cholesterol clearance may partly account for increased CVD risk with obesity.
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