Thus elastin is a key structural protein in a developing arterial wall, providing resilience and reducing wall stress. Humans are particularly sensitive to reduced elastin expression during development because of the size of their arteries. This is important because environmental factors, like vitamin D, modulate elastin expression during development. It was believed that elastin deficiency would lead to development of arterial aneurysms and dissection in a pattern similar to Marfan syndrome. We discovered, however, the opposite effect.
Mice lacking elastin die shortly after birth of arterial obliteration.
Despite normal early arterial development in these mice, subendothelial proliferation and reorganization of vascular smooth muscle cells subsequently obliterate the arterial lumen. From this we conclude that elastin has a signaling function that regulates smooth muscle proliferation and organization during arterial development. As a result, we have hypothesized that disruption of elastic fibers, particularly the internal elastic lamina, is necessary and sufficient for subendothelial proliferation of smooth muscle, a central feature of obstructive vascular disease.