Human meconium contains significant amounts of alkaline sphingomyelinase, neutral ceramidase, and sphingolipid metabolites
Human meconium contains significant amounts of alkaline sphingomyelinase, neutral ceramidase, and sphingolipid metabolites
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DOI：
10.1203/01.pdr.0000250534.92934.c2
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发表时间：
2007-01-01
影响因子：
3.6
通讯作者：
Nilsson, Ake
中科院分区：
文献类型：
--
作者：
Duan, Rui-Dong;Cheng, Yajun;Nilsson, Ake
肠碱性鞘磷脂酶（Alk-SMase）和中性神经酰胺酶可催化母乳喂养婴儿内源性鞘磷脂（SM）和母乳SM的水解。这些酶产生可能影响肠道成熟的鞘脂代谢物。Alk-SMase还使参与坏死性小肠结肠炎（NEC）发病机制的血小板活化因子（PAF）失活。我们研究了这两种酶是否在早产儿和足月儿中表达，并分析了胎粪中的Alk-SMase、中性神经酰胺酶、SM和鞘脂代谢物。从46名早产儿（胎龄23-36周）和38名足月儿（胎龄37-42周）收集胎粪，并使用C-14-胆碱标记的SM和中性神经酰胺酶使用C-14-辛酰鞘氨醇作为底物进行Alk-SM酶分析。SM，神经酰胺和鞘氨醇的分子种类进行了分析，通过高效液相色谱质谱。胎粪含有显着水平的Alk-SMase和神经酰胺酶在所有胎龄。它还含有16-24个碳分子种类的SM、棕榈酰-和硬脂酰-鞘氨醇和鞘氨醇。SM与神经酰胺、神经酰胺与鞘氨醇水平呈正相关。总之，Alk-SMase和神经酰胺酶在早产儿和足月新生儿的肠道中表达，并可能产生生物活性的鞘脂信使。
Intestinal alkaline sphingomyelinase (Alk-SMase) and neutral ceramidase may catalyze the hydrolysis of endogenous sphin-gomyelin (SM) and milk SM in human-milk fed infants. The enzymes generate sphingolipid metabolites that may influence gut maturation. Alk-SMase also inactivates platelet-activating factor (PAF) that is involved in the pathogenesis of necrotizing enterocolitis (NEC). We examined whether the two enzymes are expressed in both preterm and term infants and analyzed Alk-SMase, neutral ceramidase, SM, and sphingolipid metabolites in meconium. Meconium was collected from 46 preterm (gestational ages 23-36 wk) and 38 term infants (gestational ages 37-42 wk) and analyzed for Alk-SMase using C-14-choline-labeled SM and for neutral ceramidase using C-14-octanoyl-sphingosine as substrates. Molecular species of SM, ceramide, and sphingosine were analyzed by high-performance liquid chromatography mass spectroscopy. Meconium contained significant levels of Alk-SMase and ceramidase at all gestational ages. It also contained 16-24 carbon molecular species of SM, palmitoyl-and stearoyl-sphingosine, and sphingosine. There were positive correlations between levels of SM and ceramide and between ceramide and sphingosine levels. In conclusion, Alk-SMase and ceramidase are expressed in the gut of both preterm and term newborn infants and may generate bioactive sphingolipid messengers.