重组β-防御素2多肽对脓毒症大鼠肺组织细胞凋亡的影响

目的：观察重组β-防御素2多肽预处理对脓毒症大鼠肺组织细胞凋亡的影响。方法：SPF级SD大鼠48只随机分成对照组和防御素组，采用盲肠结扎穿孔术（CLP）复制脓毒症模型，防御素组在CLP前48h经气管插管气道滴注10^7PFU重组腺病毒（含有β-防御素2编码基因），而对照组则同法给予对照腺病毒（不合β-防御素2编码基因）。分别于CLP后0、12、36和72h处死大鼠，取肺组织，采用透射电镜，末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）检测细胞凋亡，采用电镜、苏木精-伊红（HE）染色观察肺组织病理变化。结果：TUNEL检测显示，对照组大鼠CLP后12、36和72h肺组织细胞凋亡指数显著增加（P〈0．01）；与对照组相比，防御素组CLP后相应时间点肺组织细胞凋亡指数显著降低（P〈0．05）。HE染色可见，两组大鼠CLP后12、36和72h肺泡及肺泡间质充血、水肿，炎症细胞渗出，肺泡腔不同程度狭窄。与对照组相比较，防御素组相应时间点肺组织内炎症细胞渗出减少，间质水肿减轻。结论：重组β-防御素2多肽预处理能抑制脓毒症肺组织的细胞凋亡，对急性肺损伤（ALI）具有保护作用。

Effect of recombinant β-defensin-2 peptide on apoptosis of pulmonary tissue in rats with sepsis

OBJECTIVE: To investigate the effect of recombinant beta-defensin 2 (BD-2) on the apoptosis of pulmonary tissue in rats with sepsis.METHODS: Forty-eight SD rats were randomly divided into defensin group and controls.In control group 24 rats received 10(7)PFU adenovirus via trachea intubation. In defensin group 24 rats received 10(7)PFU recombinant adenovirus carrying all expression cassette of rat BD-2 (Ad-rBD2). All rats received cecal ligation and puncture (CLP) to induce sepsis 48 h following the administration of adenovirus. Rats of both groups were sacrificed at 0, 12, 36 and 72 h after CLP; lungs were removed and fixed for Haematoxylin and Eosin (HE) stain. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) technique. RESULT: The apoptosis index (AI) of lung cells increased significantly following CLP in control group,while it was significantly lower in defensin group than that of control group (P<0.05). In addition, a significant alveolar damage, interstitial edema, and infiltration of inflammatory cells were observed in control lungs, while it was less severe in defensin group. CONCLUSION: Recombinant beta-defensin 2 may reduce the apoptosis of lung cells and attenuate lung injury.