Endometrial expression of selected transcripts involved in prostaglandin synthesis in cows with endometritis.

ABSTRACT

Several cytokines and prostaglandins play an important role in preparing the endometrium for implantation and mediating pro-inflammatory events. The aim of the present study was to examine mRNA expression of interleukin 1alpha (IL-1alpha), interleukin receptor antagonist (IL-1-RN), cytosolic prostaglandin E synthase (cPGES), microsomal PGES (mPGES-1 and mPGES-2) and lipocalin-type PGDS (L-PGDS) in the bovine endometrium. Endometrial epithelium samples were collected ex vivo from cows with different status of health at day 21-27 postpartum on a dairy farm. Three groups (n=9 animals each) were defined (1) healthy cows with no signs of endometritis (control group), (2) cows with subclinical endometritis, and (3) cows with signs of clinical endometritis. Oestrous cycle-dependent mRNA expression pattern was investigated using bovine endometrial epithelial cells from healthy uteri collected at the abattoir. These uteri were classified into post-ovulatory, early-to-mid luteal, late luteal or pre-ovulatory phase (n=8 animals for each cycle phase). After collecting endometrial epithelium using the cytobrush-method, mRNA analysis was performed by real-time RT-PCR. L-PGDS, IL-1alpha and IL-1-RN mRNA were expressed significantly higher (P<0.05) in the endometrium of cows with subclinical or clinical endometritis compared with healthy cows. A twofold lower cPGES mRNA expression (P<0.05) was detected in cows with subclinical endometritis compared to healthy cows. L-PGDS and IL-1-RN mRNA expression was increased (P<0.05) after ovulation compared with the pre-ovulatory or luteal phase, respectively. These results support the hypothesis that a dys-regulated cytokine and/or prostaglandin profile in the uterus could be induced by subclinical endometritis or clinical endometritis.