Polydeoxyribonucleotide Mitigates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice Through the PKA/CREB/NF-κB Signaling Pathway

Background/Objectives: Ulcerative colitis (UC) is a type of inflammatory bowel disease characterized by abdominal pain, diarrhea, and bleeding. Polydeoxyribonucleotide (PDRN), an adenosine A2A receptor (A2AR) agonist, exhibits anti-inflammatory properties. In the present study, we evaluated the therapeutic effects of PDRN in a dextran sodium sulfate (DSS)-induced murine model of UC. Methods: UC was induced by administering 2% DSS in drinking water for 7 days. One day after DSS administration, mice received intraperitoneal injections of PDRN (8 mg/kg) for 7 days. To investigate the involvement of A2AR, the selective antagonist 3,7-dimethyl-1-propargylxanthine (DMPX, 8 mg/kg) was co-administered with PDRN. Results: DSS administration induced colonic tissue damage and increased disease activity index (DAI) and histological scores. DSS also elevated pro-inflammatory cytokines while reducing anti-inflammatory cytokine levels. PDRN treatment reduced histological damage, restored body weight, colon weight, and colon length, and decreased DAI scores. Furthermore, PDRN treatment inhibited nuclear factor kappa B (NF-κB) activation through suppression of NF-κB inhibitor-α phosphorylation and was associated with activation of the cAMP/PKA/CREB signaling pathway. PDRN treatment attenuated inflammation and was associated with increased expression of vascular endothelial growth factor (VEGF) in colonic tissues. Given the context-dependent role of VEGF in inflammatory bowel disease, this increase is interpreted as contributing to mucosal repair rather than exacerbating inflammation. Co-administration of DMPX abolished these effects, suggesting the involvement of A2AR-dependent signaling pathways. Conclusions: PDRN attenuated colonic inflammation and improved disease outcomes in DSS-induced UC, potentially through modulation of the PKA/CREB/NF-κB signaling pathway and VEGF-mediated tissue repair mechanisms.