Journal
MATRIX BIOLOGY
Volume 27, Issue 3, Pages 171-181Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.matbio.2007.10.008
Keywords
extracellular matrix; microstructure; elastin; medial lamellar unit; smooth muscle cells; collagen; aorta
Categories
Funding
- NCRR NIH HHS [U54 RR020336-01] Funding Source: Medline
- NHLBI NIH HHS [R01 HL064327, 2R01 HL064338-05A1, R01 HL064327-08, R01 HL064338-08, R01 HL064338, 2R01 HL64327-05A1] Funding Source: Medline
- NIGMS NIH HHS [U54 GM072970] Funding Source: Medline
Ask authors/readers for more resources
Changes in arterial wall composition and function underlie all forms of vascular disease. The fundamental structural and functional unit of the aortic wall is the medial lamellar unit (MLU). While the basic composition and organization of the MLU is known, three-dimensional (3D) microstructural details are tenuous, due (in part) to lack of three-dimensional data at micro- and nano-scales. We applied novel electron and confocal microscopy techniques to obtain 3D volumetric information of aortic medial microstructure at micro- and nano-scales with all constituents present. For the rat abdominal aorta, we show that medial elastin has three primary forms: with approximately 71 % of total elastin as thick, continuous lamellar sheets, 27% as thin, protruding interlamellar elastin fibers (IEFs), and 2% as thick radial struts. Elastin pores are not simply holes in lamellar sheets, but are indented and gusseted openings in lamellae. Smooth muscle cells (SMCs) weave throughout the interlamellar elastin framework, with cytoplasmic extensions abutting IEFs, resulting in approximately 20 radial tilt (relative to the lumen surface) of elliptical SMC nuclei. Collagen fibers are organized as large, parallel bundles tightly enveloping SMC nuclei. Quantification of the orientation of collagen bundles, SMC nuclei, and IEFs reveal that all three primary medial constituents have predominantly circumferential orientation, correlating with reported circumferentially dominant values of physiological stress, collagen fiber recruitment, and tissue stiffness. This high resolution three-dimensional view of the aortic media reveals MLU microstructure details that suggest a highly complex and integrated mural organization that correlates with aortic mechanical properties. (C) 2007 Elsevier B.V./International Society of Matrix Biology. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available