Role of macrophages in adipocyte degradation – a live-imaging approach (B09 [A04])

• Subject Area: Nuclear Medicine, Radiotherapy, Radiobiology
• Term: since 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 209933838

The innate immune system is involved in tissue homeostasis due to clearance of dead cells and tissue regeneration. Every day 200 – 300 billions of dead cells have to be recognized and degraded by specialized phagocytes, so called macrophages. In contrast to other tissues, adipose tissue mainly consists of fat cells (adipocytes), which can exceed 100 µm in diameter, a dimension about 5~fold larger than regular macrophages. Hence, tissue clearing of dead adipocytes is challenging. Our preliminary data show, that single macrophages are insufficient to degrade dead adipocytes. Aim of this project is to elucidate the cellular and molecular processes following adipocyte death. Therefore, we have established ex vivo models (laser-injury of individual adipocytes) and in vivo models (transgenic expression of cell death inducers) to understand the cellular and molecular pathways leading to adipocyte degradation in living tissue. We will here focus on extracellular digestion of adipocytes via lysosomal exocytosis. Our ultimate goal is to provide pharmacological targets to improve adipocyte degradation of dead adipocytes in obesity.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1052: Obesity Mechanisms
• Applicant Institution: Universität Leipzig
• Project Heads: Professor Dr. Ingo Bechmann, until 6/2021; Professor Dr. Martin Gericke