Adenosine activates four distinct adenosine receptors suggested as A1, A2A, A2B, and also A3. These receptors are extensively revealed and also linked in several physical as well as pathological features. The A2A receptor plays the main role in modulating swelling, oxygen intake, anaemia, cell development, as well as angiogenesis. PDRN was compared to adenosine in primary cultures of human skin fibroblasts (Thellung et al., 1999): both PDRN and also adenosine caused cell development. The results of PDRN were abolished by the concomitant incubation with an adenosine A2 receptor antagonist, 3,7-Dimethyl-1-propargylxanthine (DMPX). DMPX has a greater affinity for A2A compared to for A2B receptor subtype. This leads to assume that PDRN could preferentially act upon the adenosine A2A receptor thus recommending the involvement of this receptor subtype in PDRN effects. It could be guessed that PDRN might represent a pro-drug able to generate active deoxyribonucleotides, nucleosides, and bases exerting their pharmacological results by communicating with the A2A receptor.
In additional experiments, cultured fibroblasts were filled with radioactive amino acids in the presence of PDRN (Sini et al., 1999). Under these conditions, salvage pathways run to recuperate bases and also nucleosides generated from the break down of DNA and also RNA. PDRN generates nucleotides as well as nucleosides that could add to DNA development, therefore reactivating typical cell proliferation and also development pattern.
PDRN stimulatory result on cell growth was likewise explored in human cultured osteoblasts (Guizzardi et al). PDRN (20 mg/ml) advertised cell expansion with a concomitant boost in alkaline phosphatase as well as DMPX reduced this results. PDRN has been additionally tested in primary chondrocytes (Gennero et al), where induced a physiological accumulation of the extracellular matrix with lowered proteoglycan destruction, decreasing matrix metalloproteinases 2 and 9. PDRN synergizes with glucosamine in reducing extracellular matrix gene expression, therefore lowering its degradation (Avantaggiato et al). These evidence candidates the DNA obtained drug as a possible treatment in regenerative cartilage therapy.
Additionally, PDRN could likewise secure cells from UV-induced DNA damage. Exposure of human facial fibroblasts to ultraviolet B radiation triggers a build-up of hazardous photoproducts such as cyclobutane pyrimidine dimers (CPDS).