"Lipedema: The use of cultured adipocytes for identification of diagnostic markers"

BACKGROUND: Lipedema is a progressive disease, diagnosed most often in women, which is characterized by the unproportionate and symmetrical distribution of adipose tissue primarily in the extremities. Despite numerous results from in vitro and in vivo studies, many questions regarding the pathology and genetic background of lipedema have remained unanswered. METHODS: Adipose tissue-derived stromal/stem cells (ASCs) were isolated from lipoaspirates derived from non-obese and obese lipedema and non-lipedema donors. Growth/morphology, metabolic activity, differentiation potential and gene expression were evaluated using quantification of lipid accumulation, metabolic activity assay, live-cell imaging, RT-PCR, quantitative PCR and immunocytochemical staining. RESULTS: The adipogenic potential of lipedema and non-lipedema ASCs did not rise in parallel with the donors' BMI and did not differ significantly between groups. However, in vitro differentiated adipocytes from non-obese lipedema donors showed significant upregulation of adipogenic gene expression compared to non-obese controls. All other genes tested were equally expressed in lipedema and non-lipedema adipocytes. The ADIPOQ/LEP ratio (ALR) was significantly reduced in adipocytes from obese lipedema donors compared to their non-obese lipedema counterparts. Increased stress fiber-integrated SMA was visible in lipedema adipocytes compared to non-lipedema controls and appeared enhanced in adipocytes from obese lipedema donors. CONCLUSIONS: Not only lipedema per se but also BMI of donors impact adipogenic gene expression substantially in vitro. The significantly reduced ALR and the increased occurrence of myofibroblast-like cells in "obese" lipedema adipocyte cultures underlines the importance of attention towards the co-occurrence of lipedema and obesity. These are important findings towards accurate diagnosis of lipedema.