Disordered Maternal and Fetal Iron Metabolism Occurs in Preterm Births in Human

Preterm Piglets Born by Cesarean Section as a Suitable Animal Model for the Study of Iron Metabolism in Premature Infants

Preterm infants are most at risk of iron deficiency. However, our knowledge of the regulation of iron homeostasis in preterm infants is poor. The main goal of our research was to develop and validate an animal model of human prematurity to assess iron status in preterm infants. We performed a cesarean section on sows on the 109th day of pregnancy, which corresponds to the last trimester of human pregnancy. Preterm piglets showed decreased body weight, red blood cell indices, plasma iron level and transferrin saturation. Interestingly, higher hepatic and splenic non-heme iron content and plasma and hepatic ferritin levels were found in premature piglets compared with term ones. In addition, premature piglets showed higher mRNA levels of iron-regulatory hormone hepcidin in the liver than term animals, which have not been reflected in higher plasma hepcidin-25 levels. We also showed changes in hepcidin regulators, including hepatic bone morphogenetic protein 6, plasma erythroferrone and growth differentiation factor 15 in preterm piglets. Consequently, no difference was observed in iron-exporter ferroportin levels in the spleen and liver. Overall, it seems that premature piglets show a pattern of iron metabolism characteristic of functional iron deficiency and iron accumulation in the tissue.

Identification of key metabolism-related genes and pathways in spontaneous preterm birth: combining bioinformatic analysis and machine learning

Background

Spontaneous preterm birth (sPTB) is a global disease that is a leading cause of death in neonates and children younger than 5 years of age. However, the etiology of sPTB remains poorly understood. Recent evidence has shown a strong association between metabolic disorders and sPTB. To determine the metabolic alterations in sPTB patients, we used various bioinformatics methods to analyze the abnormal changes in metabolic pathways in the preterm placenta via existing datasets.

Methods

In this study, we integrated two datasets (GSE203507 and GSE174415) from the NCBI GEO database for the following analysis. We utilized the "Deseq2" R package and WGCNA for differentially expressed genes (DEGs) analysis; the identified DEGs were subsequently compared with metabolism-related genes. To identify the altered metabolism-related pathways and hub genes in sPTB patients, we performed multiple functional enrichment analysis and applied three machine learning algorithms, LASSO, SVM-RFE, and RF, with the hub genes that were verified by immunohistochemistry. Additionally, we conducted single-sample gene set enrichment analysis to assess immune infiltration in the placenta.

Results

We identified 228 sPTB-related DEGs that were enriched in pathways such as arachidonic acid and glutathione metabolism. A total of 3 metabolism-related hub genes, namely, ANPEP, CKMT1B, and PLA2G4A, were identified and validated in external datasets and experiments. A nomogram model was developed and evaluated with 3 hub genes; the model could reliably distinguish sPTB patients and term labor patients with an area under the curve (AUC) > 0.75 for both the training and validation sets. Immune infiltration analysis revealed immune dysregulation in sPTB patients.

Conclusion

Three potential hub genes that influence the occurrence of sPTB through shadow participation in placental metabolism were identified; these results provide a new perspective for the development and targeting of treatments for sPTB.

Preterm Birth and Its Association with Maternal Diet, and Placental and Neonatal Telomere Length

Preterm birth (PTB), a multi-causal syndrome, is one of the global epidemics. Maternal nutrition, but also neonatal and placental telomere length (TL), are among the factors affecting PTB risk. However, the exact relationship between these factors and the PTB outcome, remains obscure. The aim of this review was to investigate the association between PTB, maternal nutrition, and placental-infant TL. Observational studies were sought with the keywords: maternal nutrition, placental TL, newborn, TL, and PTB. No studies were found that included all of the keywords simultaneously, and thus, the keywords were searched in dyads, to reach assumptive conclusions. The findings show that maternal nutrition affects PTB risk, through its influence on maternal TL. On the other hand, maternal TL independently affects PTB risk, and at the same time PTB is a major determinant of offspring TL regulation. The strength of the associations, and the extent of the influence from covariates, remains to be elucidated in future research. Furthermore, the question of whether maternal TL is simply a biomarker of maternal nutritional status and PTB risk, or a causative factor of PTB, to date, remains to be answered.