Evidence for the Involvement of Gene Regulation of Inflammatory Molecules in the Accumulation of Intracellular Cholesterol: The Mechanism of Foam Cell Formation in Atherosclerosis

Vasily N Sukhorukov; Victoria A Khotina; Daria D Borodko; Mariam Bagheri Ekta; Yumiko Oishi; Andrey V Omelchenko; Kira I Kolmychkova; Nikita G Nikiforov; Igor A Sobenin; Alexander N Orekhov

doi:10.2174/0109298673286400240206095814

Evidence for the Involvement of Gene Regulation of Inflammatory Molecules in the Accumulation of Intracellular Cholesterol: The Mechanism of Foam Cell Formation in Atherosclerosis

Curr Med Chem. 2024 Feb 19. doi: 10.2174/0109298673286400240206095814. Online ahead of print.

Affiliations

¹ Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 125315, Moscow, Russia.
² Laboratory of cellular and molecular pathology of cardiovascular system, Petrovsky National Research Centre of Surgery, 119991, Moscow, Russia.
³ Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo Japan.
⁴ Laboratory of Medical Genetics, Institute of Experimental Cardiology, Chazov National Medical Research Center of Cardiology, 121552, Moscow, Russia.

PMID: 38415442
DOI: 10.2174/0109298673286400240206095814

Abstract

Background: The relationship between the cellular pro-inflammatory response and intracellular lipid accumulation in atherosclerosis is not sufficiently studied. Transcriptomic analysis is one way to establish such a relationship. Previously, we identified 10 potential key genes (IL-15, CXCL8, PERK, IL-7, IL-7R, DUSP1, TIGIT, F2RL1, TSPYL2, and ANXA1) involved in cholesterol accumulation in macrophages. It should be noted that all these genes do not directly participate in cholesterol metabolism, but encode molecules related to inflammation.

Methods: In this study, we conducted a knock-down of the 10 identified key genes using siRNA to determine their possible role in cholesterol accumulation in macrophages. To assess cholesterol accumulation, human monocyte-derived macrophages (MDM) were incubated with atherogenic LDL from patients with atherosclerosis. Cholesterol content was assessed by the enzymatic method. Differentially expressed genes were identified with DESeq2 analysis. Master genes were determined by the functional analysis.

Results: We found that only 5 out of 10 genes (IL-15, PERK, IL-7, IL-7R, ANXA1) can affect intracellular lipid accumulation. Knock-down of the IL-15, PERK, and ANXA1 genes prevented lipid accumulation, while knock-down of the IL-7 and IL-7R genes led to increased intracellular lipid accumulation during incubation of MDM with atherogenic LDL. Seventeen overexpressed genes and 189 underexpressed genes were obtained in the DGE analysis, which allowed us to discover 20 upregulated and 86 downregulated metabolic pathways, a number of which are associated with chronic inflammation and insulin signaling. We also elucidated 13 master regulators of cholesterol accumulation that are immune response-associated genes.

Conclusion: Thus, it was discovered that 5 inflammation-related master regulators may be involved in lipid accumulation in macrophages. Therefore, the pro-inflammatory response of macrophages may trigger foam cell formation rather than the other way around, where intracellular lipid accumulation causes an inflammatory response, as previously assumed.

Keywords: Atherosclerosis; LDL; inflammation; lipid metabolism; macrophages; transcriptome analysis..