Lymphatic vessels: an emerging actor in atherosclerotic plaque development.
BACKGROUND
Atherosclerosis is a chronic inflammatory disease of large- to medium-sized arteries and is the main underlying cause of death worldwide. The lymphatic vasculature is critical for processes that are intimately linked to atherogenesis such as the immune response and cholesterol metabolism. However, whether lymphatic vessels truly contribute to the pathogenesis of atherosclerosis is less clear despite increasing research efforts in this field.


METHODS
PubMed and Ovid MEDLINE databases were searched. In addition, key review articles were screened for relevant original publications.


RESULTS
Current knowledge about lymphatic vessels in the arterial wall came from studies that examined the presence and location of such vessels in human atherosclerotic plaque specimens, as well as in a variety of arteries in animal models for atherosclerosis (e.g. rabbits, dogs, rats and mice). Generally, three experimental approaches have been used to investigate the functional role of plaque-associated lymphatic vessels; experimental lymphostasis was used to investigate lymphatic drainage of the arterial wall, and more recently, studies with genetic interventions and/or surgical transplantation have been performed.


CONCLUSIONS
Lymphatic vessels seem to be mostly present in the adventitial layer of the arterial walls of animals and humans. They are involved in reverse cholesterol transport from atherosclerotic lesions, and arteries with a dense lymphatic network seem naturally protected against atherosclerosis. Lymphangiogenesis is a process that is an important part of the inflammatory loop in atherosclerosis. However, how augmenting or impeding the distribution of lymphatic vessels impacts disease progression remains to be investigated in future studies.
Department of Pathology and Immunology, University of Geneva and Geneva University Hospitals, Geneva, Switzerland; Department of Medical Specializations - Cardiology, University of Geneva and Geneva University Hospitals, Geneva, Switzerland.
Issa
I
Kutkut
Merlijn J
MJ
Meens
Thomas A
TA
McKee
Marie-Luce
ML
Bochaton-Piallat
Brenda R
BR
Kwak
D000818:Animals; D050197:Atherosclerosis / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D018450:Disease Progression; D004285:Dogs; D006801:Humans; D042583:Lymphangiogenesis / Q000502:physiology; D042601:Lymphatic Vessels / Q000502:physiology*; D051379:Mice; D055806:Microvessels / Q000502:physiology; D058226:Plaque, Atherosclerotic / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D011817:Rabbits; D051381:Rats
Arterial wall; atherosclerosis; lymphangiogenesis; lymphatic vessels