Title : THP-1 cells as an in vitro platform for modeling macrophage senescence-like phenotype and primary screening of senolytic and anti-atherogenic compounds
Abstract:
Atherosclerosis is increasingly understood not merely as a disorder of lipid accumulation, but as an age-associated chronic inflammatory disease in which monocytes, macrophages, and foam cells play a central pathogenic role. Within this framework, cellular senescence and immune aging have emerged as biologically relevant mechanisms that may sustain persistent inflammation, defective lipid handling, and plaque progression. The human THP-1 cell line, derived from acute monocytic leukemia, is widely used as a reproducible in vitro model of monocyte/macrophage biology because it can be differentiated into macrophage-like cells by phorbol 12-myristate 13-acetate (PMA). At the same time, the phenotype of THP-1-derived macrophages is strongly influenced by differentiation conditions, including PMA concentration, exposure time, and recovery period, which makes protocol standardization essential. Accumulating evidence shows that THP-1-derived macrophages can develop a senescence-like phenotype in response to several pro-atherogenic and metabolic stressors, including oxidized Low-Density Lipoprotein (oxLDL), aggregated and lysosomally oxidized LDL, lipopolysaccharide, high glucose, and D-galactose. Under these conditions, the cells acquire features relevant to vascular aging and atherosclerotic progression, such as increased senescence-associated β-galactosidase activity, activation of the p53/p21 axis, reactive oxygen species accumulation, lysosomal dysfunction, persistent pro-inflammatory signaling, impaired cholesterol homeostasis, and enhanced foam cell formation. These changes are biologically meaningful because senescent macrophages and the senescence-associated secretory phenotype are increasingly implicated in chronic vascular inflammation and plaque destabilization. Thus, THP-1 cells should not be viewed as a full substitute for primary human macrophages, but rather as a practical first-line platform at the intersection of senescence, inflammation, and lipid overload. In this model, the most informative readouts for compound testing include oxLDL uptake, intracellular lipid accumulation, expression of CD36 and ACAT-1, ABCA1-dependent cholesterol efflux, secretion of IL-1β, IL-6, and TNF-α, and activation of NF-κB- and NLRP3-related pathways. Overall, current evidence supports the use of THP-1 cells primarily and early-stage screening of anti-atherogenic and candidate senescence-modulating agents, while promising senolytic compounds should undergo further validation in primary monocyte-derived macrophages, co-culture systems, and in vivo models of atherosclerosis. This work was supported by the Russian Science Foundation (Grant number 25-74-31017).
