Single-nuclear transcriptomics of lymphedema-associated adipose reveals a pro-lymphangiogenic stromal cell population.

Chronic lymphedema is a progressive, disfiguring disease that results from dysfunction of the lymphatic vasculature, causing distal accumulation of interstitial fluid, localized development of tissue edema, and expansion of subcutaneous adipose tissue (SAT). As the molecular mechanisms governing SAT remodeling in this disease are unclear, we performed single-nucleus RNA sequencing on paired control and affected SAT biopsies from patients with unilateral lymphedema. Lymphedema samples were characterized by expansion of SAA + adipocytes, pro-adipogenic stem cells, and proliferation of lymphatic capillaries. A GRIA1 + lymphedema-enriched stromal cell population expressing VEGFC , ADAMTS3 , and CCBE1 was identified, suggesting an enhanced axis of communication between adipose stem and progenitor cells (ASPCs) and lymphatic endothelial cells. Furthermore, lymphedema ASPC-conditioned media promoted lymphatic endothelial tube elongation in vitro . These findings indicate a critical role for ASPCs in regulating adipocyte differentiation and lymphatic vascular remodeling in lymphedema, and provide a valuable resource for better understanding this disease.