The effects of a mixture of oligo- and polydeoxyribonucleotides (PDRN) on the growth and protein secretion of cultured human skin fibroblasts were investigated. Both intact and DNAase-digested PDRN stimulated cell proliferation to a similar extent. When cultured fibroblasts were incubated with radioactive amino acids in the presence of intact or digested PDRN the incorporation of the tracer into secreted proteins increased significantly. This stimulation appears to be specific for certain protein components, including fibronectin. These results are interpreted assuming that PDRN and the nucleotides and nucleosides resulting from its degradation, can act as signal transducers or, alternatively, can be internalized and utilized to provide purine and pyrimidine rings for the salvage pathways.

Tendon and corneal decorins are differently iduronated dermatan sulphate/proteoglycan (DS/PG) and the biochemical parameter that differentiates type I collagens is the hydroxylysine glycoside content. We have examined the effect of tendon and corneal decorins on the individual phases (tlag, dA/dt) of differently glycosylated type I collagens fibril formation, at molar ratios PG:collagen monomer ranging from 0.15:1 to 0.45:1. The results obtained indicate that decorins exert a different effect on the individual phases of fibril formation, correlated to the degree of glycosylation of collagen: at the same PG:collagen ratio the fibril formation of highly glycosylated corneal collagen is more efficiently inhibited than that of the poorly glycosylated one (tendon). Moreover tendon and corneal decorins exert a higher control on the fibrillogenesis of homologous collagen with respect to the heterologous one. These data suggest a possible tissue-specificity of the interaction decorin/type I collagen correlated to the structure of the PG and collagen present in extracellular matrices.

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