l-Glutamine or l-alanyl-l-glutamine prevents oxidant- or endotoxin-induced death of neonatal enterocytes
l-Glutamine or l-alanyl-l-glutamine prevents oxidant- or endotoxin-induced death of neonatal enterocytes
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L-谷氨酰胺或 L-丙氨酰-L-谷氨酰胺可防止氧化剂或内毒素诱导的新生儿肠上皮细胞死亡
DOI：
10.1007/s00726-009-0243-x
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发表时间：
2009-05-01
期刊：
影响因子：
3.5
通讯作者：
Wu, Guoyao
中科院分区：
文献类型：
--
作者：
Haynes, Tony E.;Li, Peng;Wu, Guoyao
这项研究检验了 L-谷氨酰胺 (Gln) 或 L-丙氨酰-L-谷氨酰胺 (Ala-Gln) 可防止氧化剂或内毒素诱导的新生儿肠上皮细胞死亡的假设。新生猪的肠细胞迅速水解Ala-Gln并利用Gln。为了确定 Gln 或 Ala-Gln 是否具有细胞保护作用，将 IPEC-1 细胞在不含 Gln 的 Dulbecco's 改良 Eagle's-F12 Ham 培养基中培养 24 小时，该培养基含有 0、0.5、2.0 或 5.0 mM Gln 或 Ala-Gln，以及 0、0.5 mM H2O2 或 30 ng/ml 脂多糖 (LPS)。如果没有 Gln 或 Ala-Gln，H2O2 或 LPS 处理的细胞几乎完全死亡。 0.5、2 和 5 mM 的 Gln 或 Ala-Gln 剂量依赖性地使 H2O2 或 LPS 诱导的细胞死亡分别减少 14%、54% 和 95%，而 d-谷氨酰胺、丙氨酸、谷氨酸、鸟氨酸、脯氨酸、葡萄糖胺或核苷则没有效果。为了评价Gln或Ala-Gln在体内的有效性，7日龄仔猪每天两次口服Gln或Ala-Gln（3.42 mmol/kg体重）一周，然后单次腹腔注射LPS（0.1 mg/kg体重）；仔猪在24和48小时内被安乐死，以分析肠道凋亡蛋白和形态。对LPS攻击的仔猪施用Gln或Ala-Gln可增加小肠腔和血浆中的Gln浓度，减少Toll样受体4、活性caspase-3和NFkB的肠道表达，改善肠道损伤，降低直肠温度并增强生长性能。这些结果证明 Gln 或 Ala-Gln 对 H2O2 或 LPS 诱导的肠上皮细胞死亡具有保护作用。研究结果支持在目前不含 Gln 的儿科氨基酸溶液中添加 Gln 或 Ala-Gln，以预防新生儿肠道氧化损伤和炎症性疾病。
This study tested the hypothesis that L-glutamine (Gln) or L-alanyl-L-glutamine (Ala-Gln) prevents oxidant- or endotoxin-induced death of neonatal enterocytes. Enterocytes of neonatal pigs rapidly hydrolyzed Ala-Gln and utilized Gln. To determine whether Gln or Ala-Gln has a cytoprotective effect, IPEC-1 cells were cultured for 24 h in Gln-free Dulbecco's modified Eagle's-F12 Ham medium containing 0, 0.5, 2.0 or 5.0 mM Gln or Ala-Gln, and 0, 0.5 mM H2O2 or 30 ng/ml lipopolysaccharide (LPS). Without Gln or Ala-Gln, H2O2- or LPS-treated cells exhibited almost complete death. Gln or Ala-Gln at 0.5, 2 and 5 mM dose-dependently reduced H2O2- or LPS-induced cell death by 14, 54 and 95%, respectively, whereas d-glutamine, alanine, glutamate, ornithine, proline, glucosamine or nucleosides had no effect. To evaluate the effectiveness of Gln or Ala-Gln in vivo, 7-day-old piglets received one-week oral administration of Gln or Ala-Gln (3.42 mmol/kg body weight) twice daily and then a single intraperitoneal injection of LPS (0.1 mg/kg body weight); piglets were euthanized in 24 and 48 h to analyze intestinal apoptotic proteins and morphology. Administration of Gln or Ala-Gln to LPS-challenged piglets increased Gln concentrations in small-intestinal lumen and plasma, reduced intestinal expression of Toll-like receptor-4, active caspase-3 and NFkB, ameliorated intestinal injury, decreased rectal temperature, and enhanced growth performance. These results demonstrate a protective effect of Gln or Ala-Gln against H2O2- or LPS-induced enterocyte death. The findings support addition of Gln or Ala-Gln to current Gln-free pediatric amino acid solutions to prevent intestinal oxidative injury and inflammatory disease in neonates.