Fig. 8

Schematic diagram of polydeoxyribonucleotide (PDRN) treatment in IL-1β-induced impairment of chondrogenic differentiation. PDRN protects against IL-1β-induced inflammation and promotes chondrogenic differentiation of hBMSCs by activating the cAMP/PKA/CREB pathway and inhibiting NF-κB activation. Binding of PDRN to the adenosine A2A purigenic receptor activates the downstream kinase cascade which ultimately results in CREB-mediated suppression of NF-kB. Inhibition of this pathway prevents suppression of growth factors necessary for chondrocyte development such as growth hormone (GH) and insulin-like growth factor 1 (IGF-1) as well as bone morphogenic protein 2 (BMP2) expression. Suppression of these factors normally leads to apoptosis and catabolism. Thus, PDRN action via the A2A receptor effectively prevents apoptosis and supports development and differentiation of hBMSCs.