The RGD sequence in fibrillin-1 regulates mRNA expression

Fibrillins are the major components of microfibrils in the extracellular matrix of elastic and non-elastic tissues. Fibrillin-1 contains one evolutionarily conserved Arg-Gly-Asp (RGD) sequence which mediates cell-matrix interactions through cell-surface integrins. Mutations in close vicinity to the RDG sequence lead to heritable disorders, including Marfan syndrome and stiff skin syndrome. Two recombinant fibrillin-1 fragments were produced, one wild-type RGD-containing fragment and one fragment containing a mutant RGA sequence, which has been previously shown to abolish interactions with integrins. To determine the differential regulation of signaling pathways, microarray analysis of mRNA expression was conducted using Affymetrix Human Gene 2.0 ST chips. The mRNA expression levels were compared after 24 hours of interaction between human skin fibroblasts (HSFs) and the RGD- and RGA-containing fibrillin-1 fragments. Microarray analysis of HSFs was conducted for mRNAs in biological quadruplicates for each condition using Human Gene 2.0 ST chips (Affymetrix). Values are expressed as rF1M-RGA versus rF1M-WT.