Molecular determinants of cardiac lymphatic dysfunction in a chronic pressure-overload model

Area of Science:

• Cardiovascular Biology
• Lymphatic Research
• Molecular Medicine

Background:

• Cardiovascular diseases (CVDs) are linked to cardiac lymphatic dysfunction and impaired lymphatic drainage.
• Understanding the molecular mechanisms of lymphatic dysfunction is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the mechanisms of cardiac lymphatic dysfunction in mouse models of pressure-overload-induced heart failure (HF).
• To identify molecular targets for restoring lymphatic health in CVDs.

Main Methods:

• Single-cell RNA sequencing (scRNAseq) of cardiac lymphatic endothelial cells (LECs) and blood vascular endothelial cells (BECs) in murine HF models.
• Transaortic constriction (TAC) to induce pressure overload in mice.
• Validation using immunohistochemistry and human LEC cultures.

Main Results:

• Pressure overload induced lymphatic capillary expansion and valve loss in BALB/c mice, but not C57BL/6J mice.
• Differential gene expression analysis revealed reduced lymphatic junctional components in BALB/c mice post-TAC.
• A significant portion of differentially expressed genes in cardiac LECs post-TAC were also altered in IL-1β-stimulated human LECs.

Conclusions:

• Loss of lymphatic valves and lymphatic barrier dysregulation contribute to impaired drainage in pressure-overload-induced HF.
• Despite lymphangiogenesis and preserved immune cell attraction, lymphatic dysfunction persists.
• Identified molecular targets offer potential for therapeutic intervention in CVDs.