Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.
Biofabrication. 2022 Aug 19;14(4). doi: 10.1088/1758-5090/ac84b1.
Obesity prevalence has reached pandemic proportions, leaving individuals at high risk for the development of diseases such as cancer and type 2 diabetes. In obesity, to accommodate excess lipid storage, adipocytes become hypertrophic, which is associated with an increased pro-inflammatory cytokine secretion and dysfunction of metabolic processes such as insulin signaling and lipolysis. Targeting adipocyte dysfunction is an important strategy to prevent the development of obesity-associated disease. However, it is unclear how accurately animal models reflect human biology, and the long-term culture of human hypertrophic adipocytes in an2D monolayer is challenging due to the buoyant nature of adipocytes. Here we describe the development of a human 3Ddisease model that recapitulates hallmarks of obese adipocyte dysfunction. First, primary human adipose-derived mesenchymal stromal cells are embedded in hydrogel, and infiltrated into a thin cellulose scaffold. The thin microtissue profile allows for efficient assembly and image-based analysis. After adipocyte differentiation, the scaffold is stimulated with oleic or palmitic acid to mimic caloric overload. Using functional assays, we demonstrated that this treatment induced important obese adipocyte characteristics such as a larger lipid droplet size, increased basal lipolysis, insulin resistance and a change in macrophage gene expression through adipocyte-conditioned media. This 3D disease model mimics physiologically relevant hallmarks of obese adipocytes, to enable investigations into the mechanisms by which dysfunctional adipocytes contribute to disease.
肥胖症的患病率已达到流行程度，使个体面临罹患癌症和 2 型糖尿病等疾病的高风险。在肥胖症中，为了容纳过量的脂质储存，脂肪细胞会发生肥大，这与促炎细胞因子分泌增加和代谢过程（如胰岛素信号和脂肪分解）的功能障碍有关。针对脂肪细胞功能障碍是预防肥胖相关疾病发展的重要策略。然而，目前尚不清楚动物模型在多大程度上反映了人类生物学，并且由于脂肪细胞的浮力性质，在二维单层中长期培养人类肥大脂肪细胞具有挑战性。在这里，我们描述了一种人类 3D 疾病模型的开发，该模型重现了肥胖脂肪细胞功能障碍的特征。首先，将原代人脂肪来源的间充质基质细胞嵌入水凝胶中，并渗透到薄的纤维素支架中。薄的微组织形态允许高效组装和基于图像的分析。在脂肪细胞分化后，用油酸或棕榈酸刺激支架以模拟热量过载。通过功能测定，我们证明这种处理通过脂肪细胞条件培养基诱导了重要的肥胖脂肪细胞特征，例如更大的脂滴大小、基础脂肪分解增加、胰岛素抵抗和巨噬细胞基因表达的变化。这种 3D 疾病模型模拟了肥胖脂肪细胞的生理相关特征，可用于研究功能失调的脂肪细胞如何导致疾病。
