Ciao3 knockout causes acute lung injury through immune activation using single cell sequencing

Area of Science:

• Vascular Biology
• Immunology
• Genetics

Background:

• The CIAO3 mutation is linked to diffuse pulmonary arteriovenous malformations (dPAVMs).
• A patient with a CIAO3 mutation experienced a cytokine storm.
• This study investigates the role of CIAO3 in endothelial cells (ECs).

Purpose of the Study:

• To clarify the potential roles of CIAO3 in endothelial cells.
• To investigate the link between CIAO3 mutation, cytokine storm, and acute lung injury (ALI).
• To identify the immune cells and pathways involved in CIAO3-related lung pathology.

Main Methods:

• Conditional knockout of Ciao3 in mouse endothelial cells (EC-CKO).
• Cytokine level measurement, bulk and single-cell RNA sequencing (RNA-seq, scRNA-seq).
• Bioinformatic analyses including differential gene expression, pathway enrichment, protein-protein interaction, and cell communication analysis.

Main Results:

• Ciao3 knockout in mice led to increased cytokine levels and acute lung injury (ALI), indicative of immune activation.
• Tumor necrosis factor-alpha (TNF-α) inhibition reversed ALI, confirming inflammatory activation as the cause.
• scRNA-seq revealed altered immune cell populations and abnormal EC-immune cell communication, with monocytes and macrophages identified as key effectors.
• Upregulation of CypA and macrophage infiltration were confirmed via immunohistochemistry.

Conclusions:

• Ciao3 knockout induces ALI in mice through immune activation.
• Monocytes and macrophages are central effectors in this process.
• Targeting these immune cells or related pathways may offer therapeutic strategies for CIAO3-associated lung diseases.