The macrophage migration inhibitory factor -173G/C polymorphism is not significantly associated with necrotizing enterocolitis in preterm infants

Difference in macrophage migration inhibitory factor between preterm and term newborns and associating clinical factors: Preliminary study

This study aimed to investigate the macrophage migration inhibitory factor (MIF) and associated clinical factors in neonates. Clinical information and blood samples were obtained from 77 neonates. Clinical details were reviewed from medical records, and MIF was measured by enzyme-linked immunosorbent assay using blood samples acquired within a week after birth. Statistical analyses were performed between plasma MIF concentration and clinical factors. Among the 77 newborn infants, 25 were born at <34 weeks of gestation (preterm), 25 at 34 to 37 weeks (late preterm), and 27 at term gestation. The mean MIF was 9849.5 ± 7187.8 pg/mL in preterm, 5718.7 ± 4596.4 in late preterm, and 5361.1 ± 3895.7 in term infants (P = .016). Among 25 preterm infants born at <34 weeks of gestation, MIF was significantly higher in infants with necrotizing enterocolitis (NEC, 19,478.6 ± 8162.4 pg/mL, n = 5) than that in infants without NEC (feeding intolerance 7173.7 ± 4203.0 pg/mL, n = 12 and others 7844.9 ± 5311.2 pg/mL, n = 8, P = .020). Elevated plasma MIF levels in the transitional period were significantly associated with preterm birth before 34 weeks of gestation and the development of NEC.

Let-7d-5p suppresses inflammatory response in neonatal rats with necrotizing enterocolitis via LGALS3-mediated TLR4/NF-κB signaling pathway

Necrotizing enterocolitis (NEC) is an acute intestinal condition accounting for severe mortality and morbidity in preterm infants. This study aimed to identify the possible roles of let-7d-5p in neonatal rats with NEC. The differentially expressed genes (DEGs) related to NEC were initially screened in silico. After establishment of NEC rat models, measurement of the expression of let-7d-5p, galectin-3 (LGALS3), Toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) as well as proinflammatory cytokines (TNF-α, IL-1β, and IL-6) was conducted. The interaction between let-7d-5p and LGALS3 or argonaute-2 (AGO2) was identified. Gain- and loss-of-function approaches were then performed in an attempt to investigate the regulatory roles of let-7d-5p and LGALS3 in inflammation and cell apoptosis in NEC neonatal rats. Let-7d-5p was poorly expressed, whereas LGALS3, TLR4, and NF-κB were highly expressed, in the intestinal tissues of NEC rats. Overexpression of let-7d-5p resulted in decreased levels of proinflammatory factors in the intestinal tissues of NEC rats. Through sequential experimentation, let-7d-5p was identified to target LGALS3 and bind to AGO2. In addition, LGALS3 silencing or LPS treatment blocked the TLR4/NF-κB signaling pathway, thereby suppressing intestinal epithelial cell apoptosis and inflammation in NEC. Collectively, let-7d-5p might exercise its inhibitory properties in the inflammatory response and intestinal epithelial cell apoptosis in NEC neonatal rats via inactivation of the LGALS3-dependent TLR4/NF-κB signaling pathway.

Surgical necrotizing enterocolitis in extremely premature neonates is associated with genetic variations in an intergenic region of chromosome 8

BackgroundTwin studies suggest that genetic factors may account for up to 50% increased risk for necrotizing enterocolitis (NEC), but genome-wide association studies for NEC are lacking.MethodsGenotyping was done on Illumina BeadChip, followed by analysis using PLINK with logistic regression under an additive model.ResultsAmong 751 extremely-low-birth-weight (<1,000 g, >401 g) neonates, 30 had surgical NEC. Two hundred and sixty-one single-nucleotide polymorphisms (SNPs) showed association with NEC at P<0.05, of which 35 were significant at P<10-7. Minor allele(s) in a cluster of SNPs spanning a 43-kb region of chromosome 8 (8q23.3) conferred an odds ratio of 4.72 (95% confidence interval (CI): 2.51-8.88) for elevated risk of NEC. Two smaller clusters on chromosome 14 and chromosome 11 exhibited P values of 10-7-10-8. The chromosome 8 cluster is in an intergenic region between CUB and Sushi multiple domains 3 (-1.43 Mb) and trichorhinophalangeal syndrome I (+542 kb). RNA sequencing in this region identified a potential novel open-reading frame corresponding to a long interspersed element-1 retrotransposable element.ConclusionGenetic variation in an intergenic region of chromosome 8 is associated with increased risk for NEC with a mechanism that is yet to be identified.