Acute hyperlipidemia initiates proinflammatory and proatherogenic changes in circulation and adipose tissue in obese women

- Short-term increase in circulating lipids was achieved using Intralipid infusion.
- Hyperlipidemia decreased the relative content of M2 macrophages in adipose tissue.
- mRNA expression of proinflammatory markers increased in adipose tissue.
- In blood relative content of monocytes was reduced and adhesion molecules increased.
- Hyperlipidemia induced inflammatory/atherogenic changes in adipose tissue and blood.

BackgroundObesity represents a high risk factor for the development of atherosclerosis and is associated with a low-grade inflammation and activation of immune cells.AimsThe aim of our study was to investigate the effect of a short-term lipid infusion on immune cells in blood and subcutaneous abdominal adipose tissue (SAAT) in obese women.MethodsSeven-hour intravenous lipid/control infusions were performed in two groups of women (n = 15, n = 10, respectively). Before and at the end of the infusion, SAAT and blood samples were obtained and relative content and phenotype of immune cells were analyzed using flow cytometry. Analysis of immune cell markers, inflammation and angiogenesis markers was performed in SAAT by RT-PCR and in plasma by immunoassays.ResultsRelative content of CD45+/14+ and CD45+/14+/16+ populations of monocytes was reduced in circulation by 21% (p = 0.004) and by 46% (p = 0.0002), respectively, in response to hyperlipidemia, which suggested the increased adhesion of these cells to endothelium. In line with this, the levels of sICAM and sVCAM in plasma were increased by 9.4% (p = 0.016), 11.8% (p = 0.008), respectively. In SAAT, the relative content of M2 monocyte/macrophages subpopulation CD45+/14+/206+/16+ decreased by 27% (p = 0.012) and subpopulations CD14+/CD206− and CD14/+TLR4+ cells increased (p = 0.026; p = 0.049, respectively). Intralipid infusion promoted an increase of mRNA levels in SAAT: RORC (marker of proinflammatory Th17 lymphocytes) by 43% (p = 0.048), MCP-1 (78%, p = 0.028) and VEGF (68.5%, p = 0.0001).ConclusionsAcute hyperlipidemia induces a proinflammatory and proatherogenic response associated with altered relative content of immune cells in blood and SAAT in obese women.