Fibrocytes drive JAK2V617F-mutated myelofibrosis: pitavastatin reverses marrow fibrosis and anemia.

Fibrocytes are the main collagen-producing cells in JAK2V617F-mutated myelofibrosis, accounting for nearly two-thirds of collagen production in the bone marrow.

• Why it matters: Understanding the cellular drivers of marrow fibrosis is crucial for developing targeted therapies, as current models focus mainly on cytokine-driven reactive processes.
• What they did: The study analyzed bone marrow samples from patients and used transgenic mice to identify fibrocytes' role, then performed high-throughput drug screening to find inhibitors like pitavastatin that reduce fibrocyte proliferation.
• The result: Pitavastatin decreased fibrocyte numbers, reduced fibrosis, and improved anemia in mice, also lowering TGF-β1 production, indicating its potential as an antifibrotic treatment in JAK2V617F-mutated myelofibrosis.