Fibrosis and bone marrow: understanding causation and pathobiology

Area of Science:

• Hematology
• Pathology
• Cell Biology

Background:

• Bone marrow fibrosis is a significant structural alteration impacting marrow function.
• The precise causes of bone marrow fibrosis, particularly in its primary form, remain incompletely understood.
• This review synthesitsizes current knowledge on the pathogenesis of marrow fibrosis.

Purpose of the Study:

• To consolidate and review the current understanding of bone marrow fibrosis.
• To explore the complex interactions and mechanisms underlying fibrogenesis in the bone marrow.
• To identify key cellular and molecular players involved in the development of bone marrow fibrosis.

Main Methods:

• A comprehensive literature search was conducted on PubMed without time restrictions.
• Keywords included 'bone marrow,' 'fibrosis,' 'growth factors,' 'cytokines,' 'chemokines,' 'mesenchymal stem cells,' and related terms.
• Relevant papers on tissue marrow fibrosis were selected and analyzed for the review.

Main Results:

• Bone marrow fibrosis results from intricate interactions among growth factors, cytokines, chemokines, and hormones.
• Fibrogenesis is triggered by the mobilization and differentiation of specific mesenchymal stem cell subsets into fibroblasts.
• Stimuli for fibrosis can originate from neoplastic cells, immune cells in infections/inflammation, and autoimmunity.

Conclusions:

• Bone marrow fibrosis is a multifactorial process involving complex cellular and molecular crosstalk.
• Mesenchymal stem cells play a crucial role, differentiating into fibroblasts and driving fibrogenesis.
• Megakaryocytes and platelets are implicated as direct or intermediary stimulators of mesenchymal stem cells in this process.