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elastic fibers

Tuesday 11 November 2003

Elastic fibers are complex extracellular matrix polymers, composed of at least 19 different proteins that comprise both the microfibrillar and the amorphous components of elastic fibers.

Tissues such as blood vessels, skin, uterus, and lung require elasticity for their function. Although tensile strength is provided by the proteins of the collagen family, the ability of these tissues to recoil is provided by elastic fibers.

Elastic fibers can stretch to several times their length and then return to their original size after release of the tension.

Structure

Morphologically, elastic fibers consist of a central core made of elastin, surrounded by a peripheral network of microfibrils.

Substantial amounts of elastin are found in the walls of large blood vessels, such as the aorta, and in the uterus, skin, and ligaments.

The peripheral microfibrillar network that surrounds the core consists largely of fibrillin, a 350-kD secreted glycoprotein, which associates either with itself or with other components of the extracellualr matrix (ECM).

The microfibrils serve as scaffolding for deposition of elastin and the assembly of elastic fibers. Inherited defects in fibrillin result in formation of abnormal elastic fibers in a fairly common familial disorder, Marfan syndrome, manifested by changes in the cardiovascular system (aortic dissection) and the skeleton.

Pathology

- germ line mutations

  • Mutations in three of the genes encoding the most abundant of these elastic fiber proteins result in a broad spectrum of elastic tissue phenotypes, ranging from skeletal and skin abnormalities to vascular and ocular defects:

- anomalies of dermal elastic fibers

  • dermal elastic fiber anomalies

See also

- pseudxanthoma elasticum (mutations in the MRP6/ABCC6 gene)
- elastic tissues