Whole-Genome Uterine Artery Transcriptome Profiling and Alternative Splicing Analysis in Rat Pregnancy

Distinct uterine artery gene expression profiles during early gestation in the stroke-prone spontaneously hypertensive rat

During pregnancy, the uterine spiral arteries undergo major vascular remodeling to ensure sufficient uteroplacental perfusion to support the fetus. In pregnancies complicated by hypertensive disorders, this remodeling is deficient leading to impaired uteroplacental blood flow and poor maternal and fetal outcomes. The underlying genetic mechanisms for failed vascular remodeling are not fully understood. This study aimed to examine the early-pregnancy-associated gene changes in the uterine arteries of spontaneously hypertensive stroke-prone rats (SHRSP) compared with their normotensive counterparts, Wistar-Kyoto rats (WKY). Uterine arteries from gestational day 6.5 WKY and SHRSP were processed for RNA-sequencing, along with virgin, age-matched controls for each strain. Gene expression changes were identified and biological pathways were implicated and interpretated using ingenuity pathway analysis (IPA). This study found that WKY uterine arteries from early pregnancy exhibit a gene expression pattern that is suggestive of a pregnancy-dependent reduction in Ca²⁺ handling and renin-angiotensin-aldosterone system (RAAS) components and an increase in ATP production. In contrast, the expression pattern of pregnant SHRSP uterine arteries was dominated by an elevated immune response and increased production of reactive oxygen species (ROS) and downstream effectors of the RAAS. These results suggest that in a rat model, hypertension during pregnancy impacts uterine artery gene expression patterns as early as the first week of pregnancy. The pathway changes involved may underlie or contribute to the adverse vascular remodeling and resultant placental ischemia and systemic vascular dysfunction observed in SHRSP in late gestation.

Identification and Characterization of Hypothalamic Alternative Splicing Events and Variants in Ovine Fecundity-Related Genes

Simple Summary

Previous studies revealed that alternative splicing (AS) events and gene variants played key roles in reproduction. However, their location and distribution in hypothalamic fecundity-related genes in sheep without the FecB mutation remain largely unknown. In this study, we performed a correlation analysis of transcriptomics and proteomics, and the results suggested several differentially expressed genes (DEGs)/differentially expressed proteins (DEPs), including galectin 3 (LGALS3), aspartoacylase (ASPA) and transthyretin (TTR), could be candidate genes influencing ovine litter size. Further analysis suggested that AS events, single nucleotide polymorphisms (SNPs) and microRNA (miRNA)-binding sites existed in key DEGs/DEPs, such as ASPA and TTR. This study provides a new insight into ovine and even other mammalian reproduction.

Abstract

Previous studies revealed that alternative splicing (AS) events and gene variants played key roles in reproduction; however, their location and distribution in hypothalamic fecundity-related genes in sheep without the FecB mutation remain largely unknown. Therefore, in this study, we described the hypothalamic AS events and variants in differentially expressed genes (DEGs) in Small Tail Han sheep without the FecB mutation at polytocous sheep in the follicular phase vs. monotocous sheep in the follicular phase (PF vs. MF) and polytocous sheep in the luteal phase vs. monotocous sheep in the luteal phase (PL vs. ML) via an RNA-seq study for the first time. We found 39 DEGs with AS events (AS DEGs) in PF vs. MF, while 42 AS DEGs were identified in PL vs. ML. No DEGs with single nucleotide polymorphisms (SNPs) were observed in PF vs. MF, but five were identified in PL vs. ML. We also performed a correlation analysis of transcriptomics and proteomics, and the results suggested several key DEGs/differentially expressed proteins (DEPs), such as galectin 3 (LGALS3) in PF vs. MF and aspartoacylase (ASPA) and transthyretin (TTR) in PL vs. ML, could be candidate genes influencing ovine litter size. In addition, further analyses suggested that AS events, SNPs and miRNA-binding sites existed in key DEGs/DEPs, such as ASPA and TTR. All in all, this study provides a new insight into ovine and even other mammalian reproduction.