Single-cell transcriptomic profiling of lung fibroblasts in a bleomycin-induced systemic sclerosis mouse model

Area of Science:

• Immunology
• Pulmonary Medicine
• Cell Biology

Background:

• Systemic sclerosis (SSc) is a severe autoimmune disease causing fibrosis, vascular issues, and immune problems, with no cure.
• Pulmonary fibrosis in SSc patients has a high mortality rate, necessitating new treatment strategies.
• Fibroblasts are crucial in fibrosis, but their exact roles in pulmonary fibrosis remain unclear.

Purpose of the Study:

• To investigate the role of distinct fibroblast subpopulations in the development of pulmonary fibrosis using single-cell RNA sequencing.
• To compare different bleomycin-induced mouse models for pulmonary fibrosis to understand disease complexity.

Main Methods:

• Single-cell RNA sequencing was used on a mouse model of pulmonary fibrosis induced by subcutaneous bleomycin.
• Comparative gene expression analysis was performed on subcutaneous and intratracheal bleomycin-induced models.

Main Results:

• Two distinct fibroblast subpopulations, nephronectin-positive (NPNT) and peptidase inhibitor 16-positive (PI16) cells, were identified.
• NPNT-positive fibroblasts, found near alveoli, showed increased extracellular matrix production after bleomycin treatment.
• Comparative analysis revealed shared and unique gene expression patterns between the two bleomycin models, indicating complex fibrotic mechanisms.

Conclusions:

• The study identified specific fibroblast subpopulations (NPNT and PI16) critical to SSc-associated pulmonary fibrosis.
• Findings provide insights into the molecular drivers of pulmonary fibrosis in SSc.
• Targeting these specific fibroblast populations or pathways could lead to novel therapeutic approaches for SSc pulmonary fibrosis.