Lung megakaryocytes display distinct transcriptional and phenotypic properties

Area of Science:

• Hematology
• Pulmonology
• Immunology

Background:

• Megakaryocytes (MKs) are primarily known to reside in bone marrow (BM) and fetal liver for platelet production.
• Emerging evidence suggests the lung as a significant, yet underappreciated, site for MKs contributing to platelet mass.
• The impact of the lung microenvironment on MK development and function remains largely unexplored compared to the BM niche.

Purpose of the Study:

• To characterize the unique phenotype of MKs residing in the lung niche.
• To investigate the functional implications of lung-resident MKs regarding platelet production and immune roles.
• To compare lung MKs with hematopoietic MKs using advanced single-cell analyses.

Main Methods:

• Application of single-cell RNA sequencing to profile primary MKs from mouse lung and hematopoietic tissues.
• Histological, ploidy, and flow cytometric analyses were employed for comprehensive characterization.
• Comparative transcriptional profiling of lung-derived versus hematopoietic-derived MKs.

Main Results:

• Lung MKs exhibit a distinct transcriptional signature compared to hematopoietic MKs.
• Lung MKs show enrichment for maturation markers, suggesting enhanced potential for platelet production.
• Lung MKs express cytokines supporting lung development and display an immune/inflammatory profile, indicating roles in microbial surveillance and antigen presentation.

Conclusions:

• The lung harbors a distinct MK population with a unique phenotype.
• The lung niche independently influences MK development and functional maturation.
• Lung MKs may play significant roles in both platelet biogenesis and local immune responses within the lung.