Ultrastructure Abnormalities in Proteoglycans, Collagen Fibrils, and Elastic Fibers in Normal and Myxomatous Mitral Valve Chordae Tendineae

Current Discoveries and Interventions for Barlow’s Disease

“…Similar changes are also noted among the chordae tendineae [37][38][39]. Chordae tendineae normally have fibrosa comprised of packed collagen fibrils intermixed with elastic fibers.…”

“…In the chordae tendineae of myxomatous mitral valves, proteoglycans are abundant to the point of disrupting the pattern between elastic fibers and collagen fibers. Elastic and collagen fibers in the outer thin layer are also degraded [37].…”

Clinical and Pathological Features of Degenerative Mitral Valve Disease: Billowing Mitral Leaflet Versus Fibroelastic Deficiency

“…3,6,[8][9][10] In addition, it has been reported that similar changes are observed in chordal tendineae. [11][12][13] In some cases, there is an identified genetic and congenital defect in the connective tissue, such as in Marfan syndrome. [14][15][16][17] Recent studies have demonstrated that mucopolysaccharide was abnormally accumulated and immune activity against extracellular matrix proteins (such as fibrin and elastin 18) and collagen I and III 19) …”

Molecular and developmental mechanisms of congenital heart valve disease

“…Fbn1 2/2 mice do not survive to weaning and demonstrate more severe valve abnormalities and loss of aortic root elastic fiber organization. Mutations in additional elastin-fiber genes, including elastin and fibulin4, result in related ECM abnormalities and thickening of the valves in mice (Schoen, 1997;Vesely, 1998;Akhtar et al, 1999;Ng et al, 2004;Hanada et al, 2007;Hinton et al, 2010). The progression of heart valve pathogenesis in mouse models of Marfan syndrome has been attributed to increased TGF-b signaling, leading to valve leaflet thickening, ECM disorganization, apoptosis, and cell proliferation (Ng et al, 2004;Hanada et al, 2007;Hinton et al, 2010;Massam-Wu et al, 2010).…”