Neutrophil extracellular traps in ischemia-reperfusion injury-induced myocardial no-reflow: therapeutic potential of DNase-based reperfusion strategy

作者:Ge, Lan; Zhou, Xin; Ji, Wen-Jie; Lu, Rui-Yi; Zhang, Yan; Zhang, Yi-Dan; Ma, Yong-Qiang; Zhao, Ji-Hong; Li, Yu-Ming*
来源:American Journal of Physiology - Heart and Circulatory Physiology, 2015, 308(5): H500-H509.
DOI:10.1152/ajpheart.00381.2014

摘要

Emerging evidence suggests a potential role of neutrophil extracellular traps (NETs) in linking sterile inflammation and thrombosis. We hypothesized that NETs would be induced during myocardial ischemia-reperfusion (I/R), and NET-mediated microthrombosis may contribute to myocardial "no-reflow". Male Wistar rats were randomly divided into I/R control, DNase (DNase I, 20 mu g/rat), recombinant tissue-type plasminogen activator (rt-PA, 420 mu g/rat), DNase + rt-PA, and sham control groups after 45-min myocardial ischemia. In situ NET formation, the anatomic "no re-flow" area, and infarct size were evaluated immediately after 3 h of reperfusion. Long-term left ventricular (LV) functional and histological analyses were performed 45 days after operation. Compared with the I/R controls, the DNase + rt-PA group exhibited reduced NET density [8.38 +/- 1.98 vs. 26.86 +/- 3.07 (per 200 x field), P < 0.001] and "no-flow" area (15.22 +/- 0.06 vs. 34.6 +/- 0.05%, P < 0.05) in the ischemic region, as well as reduced infarct size (38.39 +/- 0.05 vs. 71.00 +/- 0.03%, P < 0.001). Additionally, compared with the I/R controls, DNase + rt-PA treatment significantly ameliorated I/R injury-induced LV remodeling (LV ejection fraction: 64.22 +/- 3.37 vs. 33.81 +/- 2.98%, P < 0.05; LV maximal slope of the LV systolic pressure increment: 3,785 +/- 216 vs. 2,596 +/- 299 mmHg/s, P < 0.05). The beneficial effect was not observed in rats treated with DNase I or rt-PA alone. Our study provides evidence for the existence of NETs in I/R-challenged myocardium and confirms the long-term benefit of a novel DNase-based reperfusion strategy (DNase I + rt-PA), which might be a promising option for the treatment of myocardial I/R injury and coronary no-reflow.