An ultrasound-guided biopsy technique for obtaining supraclavicular brown fat biopsies and preadipocytes

Brown adipose tissue (BAT) is considered a potential therapeutic target for obesity and other metabolic diseases, due to its ability to convert glucose and fatty acids to heat. However, studying activated human BAT in vivo poses challenges due to its intricate anatomical positioning e.g. in the supraclavicular area. We present an ultrasound-guided biopsy technique for collecting small biopsies from the supraclavicular area and procedures for RNA extraction and adipose progenitor cell isolation from said biopsies. We show that it is possible to extract sufficient RNA for qPCR analysis and isolate adipose progenitor cells with differentiation capacity from the small biopsies. The success rate of the procedures was, however, low, with only few of the isolated progenitors being able to successfully differentiate, and most samples and cell cultures not showing a clear BAT profile. In the manuscript we discuss possible methodological refinements to yield a higher success rate. We thus present a proof of concept and a first step towards a new method for obtaining and studying human BAT, which would enable the conduction of clinical intervention studies of BAT biology in humans.