Project description:Hundreds of naturally occurring milk peptides have been found in term human milk. Whether there are differences between the levels of these peptides between term and preterm milk remains unknown. Premature milk is produced before complete maturation of the mammary gland and is under the influence of a different hormonal milieu, which could change enzymatic activity and protein expression within the mammary gland and result in an altered peptide profile. We employed nano-liquid chromatography tandem mass spectrometry to identify naturally occurring peptides in term and premature milks at multiple time-points across lactation and compare the abundances of these peptides. We found that preterm milks produced more unique peptide sequences than term milks on average (359 vs. 286). The peptides identified were searched for overlapping sequences with an in-house database of known functional peptides. Specifically, we found that both term and preterm milks contain peptides overlapping with known sequences with antimicrobial, opioid antagonist and immunomodulatory actions. We also compared the enzymes involved in degradation of both milks via bioinformatic analysis. This analysis reveals that plasmin is more active in preterm milk than term milk.
Project description:We hypothesized that preterm spontaneous labor involves aberrant changes in mRNA expression in the placenta. To test this hypothesis, we interrogated the mRNA levels of >50,000 genes and transcript variants using gene expression microarray (Human Genome U133 Plus 2.0 Array, Affymetrix) on 5 placentas collected from preterm spontaneous delivery (<34 weeks of gestation) and another 5 placentas collected from term spontaneous delivery (38-39 weeks). We have identified 229 and 162 genes that were up- or down-regulated, respectively, for more than 3-fold in the preterm placentas compared to the term placentas (Mann-Whitney Rank Sum Test, with multiple testing correction by the Benjamini-Hochberg method, adjusted p-value <= 0.05). Placentas collected from (i) preterm spontaneous delivery (<34 weeks of gestation) and (ii) term spontaneous delivery (38-39 weeks of gestation) were subjected to RNA extraction and hybridization on Affymetrix microarrays. To identify gene expression patterns that are commonly involved in preterm spontaneous labour, we analyzed 5 placentas from each of these 2 groups and tested for any differentially expressed genes by Mann-Whitney Rank Sum Test.
Project description:Preterm birth is multifactorial in origin with several distinct clinical phenotypes of differing etiologies, including idiopathic preterm birth. Preterm birth involves the interaction of genetic, societal and environmental factors such as nutrition, lifestyle and stress that may modulate the length of gestation via the epigenome. DNA methylation is a well-studied epigenetic modification whereby promoter methylation commonly represses gene expression and vice versa. Myometrial tissue was obtained at cesarean section at term with or without labor, preterm without labor, idiopathic preterm labor, and twin gestations with labor. Differences in the myometrial epigenomes were identified at gene promoters, CpG islands, CpG island shores and shelves, gene bodies across the genome between the groups of women with preterm labor of different phenotypes vs. normal term labor. Functional clustering analysis indicated the significantly enriched pathways of hypomethylated genes (permissive) were related to acute inflammatory and acute-phase responses. By contrast, genes that are hypermethylated (repressive) revealed enrichment for contractile fibers and cell. This study provides the first high-resolution DNA methylome of human myometrium with evidence for differences in the methylome that may relate to idiopathic preterm birth via regulation of gene expression. The findings extend previous observations that idiopathic preterm labor is associated with subclinical intrauterine infection and inflammatory pathways and point to targets for further molecular characterization of preterm delivery. Comparison of the human myometrial epigenomes in pregnancies with preterm labor of different phenotypes vs. normal term labor
Project description:Genome wide placental DNA methylation profiling of full term and preterm deliveries sampled from 5 full term deliveries and 4 preterm deliveries. The Illumina HumanMethylation450 Beadchip was used to obtain DNA methylation profiles across approximately 485,577 CpGs in formalin fixed samples. Samples included 4 placental tissues from 4 women with preterm delivery and 5 placental tissues from 5 women with full term delivery. 9 women's placental DNA (4 women had perterm deliveries and 5 women had full term deliveries) were hybridised to the Illumina HumanMethylation450 Beadchip
Project description:Preterm birth is a main determinant of neonatal mortality and morbidity and a major contributor to the overall mortality and burden of disease. However, precise phenotyping of the preterm birth is hampered by the imprecise definition of the clinical phenotype and complexity of the molecular phenotype due to multiple pregnancy tissue types and molecular processes that may contribute to the preterm birth. The studyâ??s aim was to comprehensively evaluate the mRNA transcriptome that characterizes preterm and term labor using precisely phenotyped samples. Expression profiles of 73 genes and non-coding RNA sequences uniquely identified the four groups of patients: delivering preterm with (PL) and without labor (PNL), term with (TL) and without labor (TNL). The largest differences in gene expression among the four groups occurred in decidua, chorion and amnion. The gene expression profiles showed suppression of chemokines expression in TNL, withdrawal of this suppression in TL, activation of multiple pathways of inflammation in PL, and an immune rejection profile in PNL. The genes constituting expression signatures showed over-representation of three putative regulatory elements in their 5â?? and 3â??UTR regions. The results suggest that pregnancy is maintained by downregulation of chemokines at the maternal-fetal interface. Withdrawal of this downregulation results in the term birth and its overriding by the activation of multiple pathways of the immune system in the preterm birth. Complications of the pregnancy associated with impairment of placental function, which necessitated premature delivery of the fetus in the absence of labor, show gene expression patterns associated with immune rejection. 183 total RNA samples from 8 tissue types collected from 35 women grouped into six categories of pregnancy outcome. One microarray replicate per sample. Other Contributors: Radek Bukowski, Sam Parry and the NICHD Genomic and Proteomic Network for Preterm Birth Research
Project description:Comparing miRNAs expression levels in chorioamniotic membranes from women at term in labor (TL), women at term not in labor (TNL) and women who deliverd preterm (PTLC). The goal was to see if miRNA levels are indicators of preterm delivery or spontaneous labor at term. A two-channel technology was used in this experiment in which a pooled reference RNA was used for competitive hybridization. The pooled reference was generated at Exiqon in Denmark from a mixture of several human tissues (placenta, thyroid, brain, adipose, spleen, liver, colon, skeletal muscle, ovary, kidney, heart, cervix, testes, esophagus, small intestine, prostate, trachea, thymus, bladder, lung).
Project description:We hypothesized that preterm spontaneous labor involves aberrant changes in mRNA expression in the placenta. To test this hypothesis, we interrogated the mRNA levels of >50,000 genes and transcript variants using gene expression microarray (Human Genome U133 Plus 2.0 Array, Affymetrix) on 5 placentas collected from preterm spontaneous delivery (<34 weeks of gestation) and another 5 placentas collected from term spontaneous delivery (38-39 weeks). We have identified 229 and 162 genes that were up- or down-regulated, respectively, for more than 3-fold in the preterm placentas compared to the term placentas (Mann-Whitney Rank Sum Test, with multiple testing correction by the Benjamini-Hochberg method, adjusted p-value <= 0.05).
Project description:Genome wide placental DNA methylation profiling of full term and preterm deliveries sampled from 5 full term deliveries and 4 preterm deliveries. The Illumina HumanMethylation450 Beadchip was used to obtain DNA methylation profiles across approximately 485,577 CpGs in formalin fixed samples. Samples included 4 placental tissues from 4 women with preterm delivery and 5 placental tissues from 5 women with full term delivery.
Project description:To further explore the underlying mechanisms of the protection functions of human milk exosmes, high throughput sequencings were used to identify differentially expressed lncRNA and mRNA profiles between human milk exosomes form term human breast milk (Term-Exos) and preterm human breast milk (Pre-Exos).