Efficient aortic lymphatic drainage is necessary for atherosclerosis regression induced by ezetimibe

Area of Science:

• Cardiovascular Biology
• Lymphatic Research
• Atherosclerosis Pathogenesis

Background:

• Functional lymphatic vasculature is crucial for maintaining tissue fluid balance, immune responses, and lipid transport.
• While atherosclerosis is associated with lymphangiogenesis in the adventitia, the function of aortic lymphatic vessels in this disease remains uncharacterized.
• The precise role of lymphatic drainage in the development and progression of atherosclerosis is not well understood.

Purpose of the Study:

• To assess the functionality of aortic lymphatic vessels during atherosclerosis progression and regression.
• To investigate the impact of impaired aortic lymph flow on atherogenesis.
• To explore the therapeutic potential of enhancing lymphatic drainage in atherosclerosis.

Main Methods:

• Development of a novel method to measure the transport of macromolecules by aortic lymphatic vessels.
• Assessment of lymphatic transport in hypercholesterolemic mouse models of atherosclerosis.
• Intervention studies involving lymphatic ligation and treatment with ezetimibe to modulate atherosclerosis and lymphatic function.

Main Results:

• Aortic lymphatic transport of macromolecules is significantly impaired as atherosclerosis progresses.
• Treatment with ezetimibe ameliorates lymphatic dysfunction during atherosclerotic lesion regression.
• Disruption of aortic lymph flow exacerbates adventitial inflammation and atherosclerotic plaque development, while inhibiting regression.

Conclusions:

• Aortic lymph stasis, characterized by reduced lymphatic clearance of atherogenic factors, contributes to atherosclerosis progression.
• Impaired lymphatic drainage, rather than solely increased atherogenic factor entry, plays a significant role in arterial wall pathology.
• Enhancing lymphatic drainage presents a promising therapeutic avenue for managing atherosclerosis.