Although high-mobility group box-1 (HMGB1) is related to the persistent intestinal inflammation in the development of necrotizing enterocolitis (NEC), the role of HMGB1 in the regulation of the intestinal microcirculation in NEC is not well understood. Therefore, we investigated the mechanism(s) by which HMGB1 regulates the generation of the following vasodilatory signals during the development of NEC: endothelial nitric oxide synthase (eNOS) and nitric oxide (NO). Experimental NEC was induced in full-term C57BL/6 mouse pups through the formula gavage and hypoxia technique. The blockade of HMGB1 was achieved with a subcutaneous injection of anti-HMGB1 antibody. Intestinal tissues and blood samples were collected at predetermined time points for the assessment of intestinal microcirculation, lipid peroxidation levels, and evaluation of eNOS activation. We found elevations in HMGB1 expression as early as 12 h after induction of NEC stress, which preceded intestinal injury. Treatment of mouse pups with HMGB1 neutralizing antibody attenuated the intestinal microvascular features and symptoms of NEC, but this improvement was not found in the eNOS knockout mice, suggesting that HMGB1 inhibition increased intestinal microcirculatory perfusion in an eNOS-dependent manner. Moreover, HMGB1 inhibition rescued NO production and eliminated O₂^•− production in experimental NEC mice through eNOS activation. These data indicate that excessive HMGB1 signaling is associated with the pathogenesis of NEC, suggesting that HMGB1 inhibition might be a promising strategy for NEC treatment.

中文翻译：

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高迁移率组 Box-1 在小鼠实验性坏死性小肠结肠炎的发病机制中至关重要

虽然高迁移率组框1（HMGB1）与坏死性小肠结肠炎（NEC）发展中的持续肠道炎症有关，但HMGB1在NEC肠道微循环调节中的作用尚不清楚。因此，我们研究了 HMGB1 在 NEC 发展过程中调节以下血管扩张信号产生的机制：内皮一氧化氮合酶 (eNOS) 和一氧化氮 (NO)。通过配方灌胃和缺氧技术在足月 C57BL/6 小鼠幼崽中诱导实验性 NEC。HMGB1 的阻断是通过皮下注射抗 HMGB1 抗体来实现的。在预定时间点收集肠道组织和血液样本，用于评估肠道微循环、脂质过氧化水平、和 eNOS 激活的评估。我们发现早在诱导 NEC 应激后 12 小时 HMGB1 表达就会升高，这在肠道损伤之前。用 HMGB1 中和抗体处理小鼠幼崽可减轻 NEC 的肠道微血管特征和症状，但在 eNOS 敲除小鼠中未发现这种改善，这表明 HMGB1 抑制以 eNOS 依赖性方式增加了肠道微循环灌注。此外，HMGB1 抑制挽救了 NO 的产生并消除了 O 表明HMGB1抑制以eNOS依赖性方式增加肠道微循环灌注。此外，HMGB1 抑制挽救了 NO 的产生并消除了 O 表明HMGB1抑制以eNOS依赖性方式增加肠道微循环灌注。此外，HMGB1 抑制挽救了 NO 的产生并消除了 O₂ ^•−通过eNOS 激活在实验性NEC 小鼠中产生。这些数据表明过度的 HMGB1 信号传导与 NEC 的发病机制相关，表明 HMGB1 抑制可能是 NEC 治疗的有希望的策略。