elastiini

Elastiini, in many languages referring to elastin, is a major extracellular matrix protein that provides elasticity to connective tissues. It forms elastic fibers together with microfibrils, producing tissues capable of stretching and returning to their original shape. Elastin is highly hydrophobic, cross-linked at many sites, and forms a durable, resilient network that persists in tissues over long periods.

Elastin is synthesized as the secreted precursor tropoelastin by fibroblasts and smooth muscle cells. Tropoelastin molecules assemble on a scaffold of fibrillin-containing microfibrils, and cross-linking by the enzyme lysyl oxidase creates desmosine and isodesmosine bonds. This cross-linking yields a stable, cross-linked core of elastin surrounded by microfibrillar components, enabling durable elastic fibers in tissues.

Elastiini is particularly abundant in tissues that require repeated stretch, such as arterial walls (notably the aorta), lungs, skin, ligaments, and the vocal cords. The elastic fibers permit tissues to elongate under force and recoil afterward, contributing to vascular compliance, airway mechanics, and skin elasticity. Elastin itself is long-lived and is not rapidly renewed; turnover involves limited synthesis of new elastin and gradual degradation of existing fibers.

Aging and disease can impair elastin integrity. Elastin degrades under the influence of elastases and matrix metalloproteinases, and elastic fiber networks weaken with age, contributing to arterial stiffening, reduced lung compliance, and wrinkling of the skin. Genetic and developmental disorders affecting elastiini include mutations in the ELN gene, linked to conditions such as cutis laxa and supravalvular aortic stenosis; the ELN deletion is also involved in Williams syndrome. Research explores elastin biology for tissue engineering and potential therapies to restore elastic properties.