Elastin
A protein providing elasticity to skin, blood vessels, and lungs. Elastin production declines significantly with age and is not efficiently regenerated, contributing to wrinkles and vascular stiffness. Research into peptides that stimulate elastin production or protect existing elastin is an active area.
Technical Context
Elastin is encoded by a single gene (ELN) and produced primarily during foetal development and early childhood — adult elastin production is minimal (<1% per year turnover). The elastin precursor tropoelastin (approximately 72 kDa) is secreted by fibroblasts, cross-linked extracellularly by lysyl oxidase to form desmosine and isodesmosine crosslinks (unique to elastin), and deposited onto a microfibrillar scaffold of fibrillin-1 (mutations in fibrillin-1 cause Marfan syndrome). Mature elastic fibres can stretch to 150% of their resting length and recoil. Elastin degradation: neutrophil elastase and MMP-12 (macrophage metalloelastase) are the primary elastin-degrading enzymes. UV exposure induces MMP expression, accelerating elastin degradation (solar elastosis — the accumulation of degraded, non-functional elastin is a hallmark of photoaged skin). Because adult elastin replacement is minimal, preventing degradation is more impactful than stimulating synthesis for maintaining skin elasticity.