The results of the present study indicate that PKCε, activated by DCP-LA, increases elastin and fibulin-5/DANCE in the extracellular space of cultured fibroblasts by the mechanism independent of transcriptional and translational modulation or inhibition of elastolysis.
A missense mutation in fibulin-5, encoding a widely expressed constituent of the extracellular matrix that has an essential role in elastic fibre assembly and has been shown to cause cutis laxa, was detected as the only novel non-synonymous sequence variant within the disease interval.
FBLN5 mutations are associated with two distinct human diseases, age-related macular degeneration (AMD) and cutis laxa (CL), but the biochemical basis for the pathogenic effects of these mutations is poorly understood.
Missense mutations in fibulin 5 cause the elastin disorder cutis laxa and have been associated with age-related macular degeneration, a leading cause of blindness.
Fibulin 5 secretion was significantly reduced (P<0.001) for four ARMD (p.G412E, p.G267S, p.I169 T, and p.Q124P) and two cutis laxa (p.S227P, p.C217R) mutations.
Histological analysis of skin sections from a cutis laxa patient with a homozygous S227P mutation showed a lack of fibulin-5 in the extracellular matrix and a concomitant disorganization of dermal elastic fibers.
Mutations in major structural components of elastic fibres, especially elastin, fibrillins and fibulin-5, cause severe, often life-threatening, heritable connective tissue diseases such as Marfan syndrome, supravalvular aortic stenosis and cutis laxa.
Cutis laxa (CL) is a heterogeneous group of genetic and acquired disorders with at least two autosomal dominant forms caused by mutations in the elastin and fibulin-5 genes, respectively.
The results demonstrate that a heterozygous mutation in fibulin-5 can cause cutis laxa and also suggest that fibulin-5 and elastin gene mutations are not the exclusive cause of the disease.
The results demonstrate that a heterozygous mutation in fibulin-5 can cause cutis laxa and also suggest that fibulin-5 and elastin gene mutations are not the exclusive cause of the disease.
Molecular study of the fibulin-5 (FBLN5) gene in a large consanguineous Turkish family with four patients affected by AR cutis laxa type I demonstrated the presence of a homozygous missense mutation (T998C) in the FBLN5 gene resulting in a serine-to-proline (S227P) substitution in the fourth calcium-binding epidermal growth factor-like domain of fibulin-5 protein.