Uterine infection-induced transcriptomic changes in the bovine endometrium

Uterine infections negatively impact cow health and productivity, increasing herd health costs, infertility, and culling. They also interfere with immune efficiency, sperm transport, embryonic development, and implantation, thus leading to pregnancy failure and infertility. Most previous studies have focused on transcriptomic changes induced by uterine infection in dairy cows. The present study aimed to investigate the changes in the endometrial transcript caused by uterine infections in beef cows.

To achieve this, we examined the reproductive tract of over 200 Angus cows at a local slaughterhouse and collected intercaruncular endometrial tissues from a subset of infected cows (uteri filled with pus) and normal cyclic cows (n = 5/group). After isolating total RNA, the samples were subjected to high-throughput RNA sequencing (n = 5/group), and differentially expressed genes were validated using qPCR.

RNA seq revealed 954 differentially expressed genes (538 upregulated and 416 downregulated) in the bovine endometrium compared to infectious and normal uterine samples. The Ingenuity Pathway Analysis (IPA) showed 822 genes enriched in the bovine endometrium, with 530 upregulated and 292 downregulated in response to uterine infection. The activated immune system components include TLR receptors, NLR receptors, RLR receptors, cytokines, and chemokines. This enrichment of genes and molecules affects various biological processes and pathways, such as inflammatory and immune responses, cytokine-cytokine receptor interaction, and chemokine signaling.

In summary, uterine infection alters the transcriptomic profile of the endometrium in infectious beef cows, potentially leading to pregnancy failure and infertility.