Depot-Specific Immunocompetent Adipoids Reveal Distinct Cardiac Adipose Tissue Identity

All articles of this category (opens in new window) Background: Adipose tissue (AT) is a heterogeneous organ with depot- and cell type-specific properties that modulate cardiovascular processes. Cardiac AT, due to its anatomical proximity and paracrine activity, closely interacts with the myocardium and can exert both protective and pathogenic effects. Conventional 2D cultures fail to capture this complexity. We therefore developed immunocompetent cardiac Adipoids (cAd), a 3D organoid model exhibiting multilocular beige-like adipocytes that build their own ECM and resident immune cells, including T cells. This model provides a controlled platform to study depot-specific mechanisms and immune-mediated effects on cardiac physiology. Methods: Ad were generated from cardiac and perigonadal AT of healthy Wistar rats. After SVF isolation, 3D spheroids are subjected to adipogenic differentiation. These matured spheroids, called Ad, were maintained in DMEM and challenged with LPS to assess inflammatory responses. Structural features were analyzed by confocal (total Ad) and fluorescent (cryosections) microscopy, while immune and stromal cell populations were characterized by flow cytometry. Proteomic profiling revealed depot-specific signatures, analyzed through bioinformatic tools. Results: cAd and perigonadal Ad (pAd) preserved depot-specific identities. cAd displayed multilocular lipid droplets typical of beige AT, while pAd contained large unilocular droplets typical of white AT. Proteomics revealed that in pAd, exclusively detected proteins were linked to adipogenesis, oxidative phosphorylation, and fatty acid metabolism. In cAd, exclusive proteins were associated with epithelial-mesenchymal transition, myogenesis, and protein secretion, while upregulated proteins included calcium signaling and ECM-related factors. Both contained macrophages and T cells. Functionally, pAd exhibited stronger proinflammatory responses to LPS, secreting higher IL6, CCL2, and CXCL1, while cAd showed lower susceptibility. These findings highlight depot-specific phenotypes, immune composition, and inflammatory potential in Ad. Conclusion: In this study, we present the first immunocompetent cAd model, which reproduces native cardiac AT morphology by developing beige-like adipocytes. These Ad generate their own ECM, contain a functional immune cell landscape, and display protein expression patterns linked to mechanical stimuli and calcium signaling. This model enables functional studies of depot-specific roles in heart failure and guides the development of cardioprotective therapies. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany