Procr+ endothelial progenitor cells govern hematopoiesis through fine-tuning mesenchymal stem cell niche signals.

Procr+ endothelial progenitor cells regulate hematopoiesis by activating MSC niche signals through a conserved Procr/HSPA8/Foxc2/Dll4 pathway.

• Why it matters: Understanding how niche cells coordinate to maintain hematopoietic stem cells (HSCs) is crucial for developing therapies for blood disorders and regenerative medicine, yet the mechanisms remain unclear.
• What they did: The study identified Procr+ endothelial cells in bone marrow with progenitor-like properties, using endothelial-specific ablation and molecular analyses to uncover their role in vascular and niche regulation, including experiments with human cells.
• The result: Procr+ EPCs sustain vascular integrity and instruct mesenchymal stem cell signaling to support HSC self-renewal, revealing a conserved pathway that offers potential for targeted niche regeneration therapies.