Table 1_DEmiRNA-mRNA regulatory network reveals miR‐122-5p as a regulatory factor of arginine metabolism in necrotizing enterocolitis.xlsx

ObjectiveNecrotizing enterocolitis (NEC) is a gastrointestinal emergency with relatively high morbidity and mortality in neonates. The role of microRNAs (miRNAs) in NEC is not yet entirely clear. This study aimed to explore the mechanism of miR-122-5p in NEC.
MethodsDifferentially expressed (DE) miRNAs were sequenced in control and NEC mice. The DEmiRNA-mRNA regulatory network was constructed and the bioinformatics analysis was performed to identify the target mRNAs and potential roles of the DEmiRNAs. The miR-122-5p activation was explored in vitro in the human intestinal epithelial cell (FHs74Int) and rat intestinal epithelial cell (IEC-6). In vivo, mice were transinfected with miR-122-5p inhibitor before the NEC occurred. Mass spectrometry was used to qualify the concentrations of amino acids, and the viability of intestinal stem cell (ISC) was accessed to verify the biological function.
ResultsPreliminarily, 15 miRNAs were found to be differentially expressed between NEC group and control group. Subsequent bioinformatics analysis revealed that miR-122-5p significantly contributes to the arginine metabolism in NEC through the DEmiRNA-mRNA regulatory network, with PRODH2 and ALDH18A1 being identified as its target genes. In vitro, miR-122-5p mimic inhibited the expression of PRODH2 and ALDH18A1 in the FHs74Int cells and IEC-6 cells. In vivo, inhibition of miR-122-5p led to increased expression of PRODH2 and ALDH18A1, along with elevated arginine levels. Following transfection with a miR-122-5p inhibiting adenovirus, the survival rate of NEC mice improved, and intestinal injury was alleviated.
ConclusionMiR-122-5p inhibition could impact arginine metabolism by targeting PRODH2 and ALDH18A1, thereby mitigating intestinal injury in NEC.

研究目的
坏死性小肠结肠炎（Necrotizing enterocolitis, NEC）是新生儿群体中发病率与死亡率均较高的胃肠道急重症。微小RNA（microRNAs, miRNAs）在NEC中的作用尚未完全阐明。本研究旨在探讨miR-122-5p在NEC中的作用机制。

研究方法
本研究对对照组与NEC模型小鼠的差异表达（differentially expressed, DE）miRNAs进行测序。构建差异表达miRNA-mRNA调控网络，并通过生物信息学分析筛选靶mRNA及差异表达miRNAs的潜在功能。分别在人肠上皮细胞（FHs74Int）与大鼠肠上皮细胞（IEC-6）中体外探究miR-122-5p的调控活性。体内实验中，在NEC造模前向小鼠体内转染miR-122-5p抑制剂。采用质谱法定量检测氨基酸浓度，并检测肠干细胞（intestinal stem cell, ISC）活性以验证其生物学功能。

研究结果
初步筛选得到15个在NEC组与对照组间存在差异表达的miRNAs。后续生物信息学分析显示，通过差异表达miRNA-mRNA调控网络，miR-122-5p可通过调控精氨酸代谢在NEC中发挥显著作用，PRODH2与ALDH18A1被鉴定为其靶基因。体外实验中，miR-122-5p模拟物可抑制FHs74Int细胞与IEC-6细胞中PRODH2与ALDH18A1的表达。体内实验显示，抑制miR-122-5p可上调PRODH2与ALDH18A1的表达，并提升精氨酸水平。转染miR-122-5p抑制型腺病毒后，NEC模型小鼠的存活率显著提升，肠道损伤得以缓解。

研究结论
抑制miR-122-5p可通过靶向PRODH2与ALDH18A1影响精氨酸代谢，从而减轻NEC小鼠的肠道损伤。