Isolation and Culturing of Primary Murine Adipocytes from Lean and Obese Mice.

Adipose tissue is primarily composed of mature, lipid-laden adipocytes by volume. These postmitotic cells play a critical role in energy storage and mobilization, thermoregulation, and the secretion of endocrine factors. The expansion of white adipose tissue due to caloric imbalance results in both the enlargement of existing adipocytes and the generation of additional adipocytes from adipocyte progenitor cells. Obesity-driven changes to white adipose tissue, including those affecting adipocytes, are associated with numerous comorbidities, such as type 2 diabetes and 13 types of cancer. A significant barrier to studying how adipocytes contribute to disease is the inability to readily isolate and culture mature adipocytes. This article describes a protocol to isolate murine lean and obese adipocytes from the subcutaneous and visceral fat depots of male and female C57BL/6 mice. The protocol details how isolated primary adipocytes can be cultured in a membrane adipocyte aggregate system for up to 2 weeks, facilitating their functional analysis in co-culture experiments, lipolysis assays, or through the collection of conditioned media containing adipocyte-secreted factors. Additionally, the protocol outlines methods for culturing adipose tissue explants in basement membrane matrix domes and imaging primary isolated adipocytes. Importantly, this approach can be integrated with existing protocols for the isolation of adipose tissue-resident adipocyte progenitor cells using fluorescence-activated cell sorting (FACS). Together, these protocols provide researchers with tools to functionally study adipocytes, adipocyte progenitor cells, and whole adipose tissue from lean and obese, male and female mice.