Characterization of an adipocytes: macrophages co-culture to model healthy and inflamed adipose tissue using proteomics

According to the World Health Organization, the current prevalence of obesity is considered pandemic, with 43% of adults globally being overweight in 2022, defined as having a body mass index (BMI) greater than 25, and 16% being obese (BMI>30), with a rising trend. Apart from genetic predisposition, hypercaloric nutrition, and low physical activity, endocrine‑disrupting chemicals (EDCs), e.g. plastic additives have been linked to obesity and the development of metabolic syndrome. Adipocytes and macrophages are essential targets for EDC-mediated effects in adipose tissue, with plastic additives such as bisphenols or phthalates shown to impair both cell types, causing adipose tissue dysfunction and disruption of homeostasis.

To elucidate the effects of EDCs on the interplay of adipocytes and macrophages and their function, a co-culture system was established, and interactions were investigated. For this purpose, cells were seeded in the following ratios: 1:1, 2:1 and 10:1 (SGBS adipocytes:THP-1 macrophages), to model healthy and inflamed adipose tissue. The global protein profiles were determined using LC-MS/MS-based proteomics, revealing significant changes in both cell types. When co-cultivating SGBS and THP-1 cells in a ratio of 2:1, THP-1 macrophages exhibited an altered glucose metabolism (pentose phosphate pathway, glycolysis, gluconeogenesis, galactose and fructose mannose metabolism). These pathways were slightly upregulated. While pathway analysis of SGBS adipocytes displayed a significant upregulation of unsaturated fatty acid biogenesis, fatty acid metabolism, glycolysis, citrate cycle, and PPAR signaling pathway when cells were co-cultivated 2:1 and 10:1. These findings demonstrate that the established co-culture system is a valuable tool for investigating the interaction between adipocytes and macrophages, and the molecular effects of EDCs that may be involved in the development of on obesity.