Dynamic pathology for circulating free DNA in a dextran sodium sulfate colitis mouse model.

PURPOSE: In sepsis, circulating free DNA (cf-DNA) is increased, and is a marker of severity and prognosis of septic patients. This study aimed to evaluate cf-DNA in a dextran sodium sulfate-induced colitis mouse model, and its clinical implications.

METHODS: Dynamic pathology of the cecum wall in the DSS-induced colitis mouse model was analyzed using multiphoton microscopy (MPM). Plasma cf-DNA concentrations in colitis mouse were quantified using PicoGreen dsDNA Assay Kit. Plasma cf-DNA was also measured in 123 human ulcerative colitis (UC) patients [mean age: 35.9 years (3-75 years) with 20 pediatric patients] to assess its relationships with clinical severity and Matt's grade.

RESULTS: Real-time images of cf-DNA were detected in the colitis model. The amount of labeled cf-DNA in the circulation of the colitis mice group was significantly higher compared with that in the control group (P < 0.05). In human UC blood samples, plasma cf-DNA concentrations in UC patients were significantly positively correlated with the clinical severity of UC and Matt's grade (P < 0.05, P < 0.05, respectively).

CONCLUSIONS: Using MPM, we observed and analyzed real-time images of cf-DNA in a colitis mouse model. Plasma cf-DNA is a potential non-invasive blood marker for reflecting clinical severity and mucosal damage in UC patients.