Department of Surgery, Section of Pediatric Surgery, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana; Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
J Surg Res. 2019 Feb;234:294-302. doi: 10.1016/j.jss.2018.08.048. Epub 2018 Oct 23.
Necrotizing enterocolitis (NEC) in premature infants is often a devastating surgical condition with poor outcomes. GYY4137 is a long-acting donor of hydrogen sulfide, a gasotransmitter that is protective against intestinal injury in experimental NEC, likely through protection against injury secondary to ischemia. We hypothesized that administration of GYY4137 would improve mesenteric perfusion, reduce intestinal injury, and reduce inflammatory responses in experimental NEC and ischemia-reperfusion injury, and that these benefits would be mediated through endothelial nitric oxide synthase-dependent pathways.
NEC was induced in C57BL/6 wild-type (WT) and endothelial nitric oxide synthase (eNOS) knockout (eNOSKO) pups via maternal separation, formula feeding, enteral lipopolysaccharide, and intermittent hypoxic and hypothermic stress. Pups received daily intraperitoneal injections of 50 mg/kg GYY4137 or phosphate buffered saline vehicle. In separate groups, adult male WT and eNOSKO mice underwent superior mesenteric artery occlusion for 60 min. Before abdominal closure, 50 mg/kg GYY4137 or phosphate buffered saline vehicle was administered into the peritoneal cavity. Laser doppler imaging was used to assess mesenteric perfusion of pups at baseline and on postnatal day 9, and the adult mice at baseline and 24 h after ischemic insult. After euthanasia, the terminal ileum of each animal was fixed, paraffin embedded, sectioned, and stained with hematoxylin and eosin. Sections were blindly graded using published injury scores. Intestinal tissue was homogenized and cytokines measured by ELISA. Data were compared using Mann-Whitney U test, and P-values <0.05 were significant.
After NEC and ischemia reperfusion (I/R) injury, GYY4137 improved perfusion in WT mice compared to vehicle, but this effect was lost in the eNOSKO animals. Histologic injury followed a similar pattern with reduced intestinal injury in WT mice treated with GYY4137, and no significant improvement in the eNOSKO group. Cytokine expression after GYY4137 administration was altered by the ablation of eNOS in both NEC and I/R injury groups, with significant differences noted in Interleukin 6 and vascular endothelial growth factor.
GYY4137, a long-acting donor of hydrogen sulfide, has potential as a therapeutic compound for NEC. It improves mesenteric perfusion and intestinal injury in experimental NEC and intestinal I/R injury, and these benefits appear to be mediated through eNOS-dependent pathways.
早产儿坏死性小肠结肠炎（NEC）常导致严重的手术并发症，预后不良。GYY4137 是一种硫化氢的长效供体，作为一种气体递质，可在实验性 NEC 中保护肠道免受损伤，这可能是通过防止由缺血引起的损伤。我们假设 GYY4137 的给药会改善肠系膜灌注，减轻肠道损伤，并减轻实验性 NEC 和缺血再灌注损伤中的炎症反应，而这些益处将通过内皮型一氧化氮合酶（eNOS）依赖的途径介导。
通过母体分离、配方喂养、肠内脂多糖和间歇性低氧、低体温应激，诱导 C57BL/6 野生型（WT）和内皮型一氧化氮合酶（eNOS）敲除（eNOSKO）幼仔发生 NEC。幼仔每天接受 50mg/kg GYY4137 或磷酸盐缓冲盐水（PBS）载体的腹腔内注射。在单独的组中，成年雄性 WT 和 eNOSKO 小鼠接受肠系膜上动脉闭塞 60 分钟。在腹部关闭前，将 50mg/kg GYY4137 或 PBS 载体注入腹腔。使用激光多普勒成像在出生后第 9 天评估幼仔的肠系膜灌注，并在缺血性损伤后 24 小时评估成年小鼠的肠系膜灌注。安乐死后，固定每个动物的末端回肠，石蜡包埋，切片，用苏木精和伊红染色。使用已发表的损伤评分对切片进行盲法评分。将肠组织匀浆并通过 ELISA 测量细胞因子。使用曼-惠特尼 U 检验比较数据，P 值<0.05 为差异有统计学意义。
在 NEC 和缺血再灌注（I/R）损伤后，与载体相比，GYY4137 改善了 WT 小鼠的灌注，但在 eNOSKO 动物中这种作用消失了。组织学损伤也呈现出类似的模式，WT 小鼠经 GYY4137 治疗后肠道损伤减轻，而 eNOSKO 组则无明显改善。在 NEC 和 I/R 损伤组中，eNOS 的消融改变了 GYY4137 给药后的细胞因子表达，白细胞介素 6 和血管内皮生长因子有显著差异。
GYY4137 是一种硫化氢的长效供体，作为一种治疗性化合物，具有治疗 NEC 的潜力。它可改善实验性 NEC 和肠道 I/R 损伤中的肠系膜灌注和肠道损伤，这些益处似乎通过 eNOS 依赖的途径介导。
