Summer heat stress affects prostaglandin synthesis in the bovine oviduct

Abstract

Summer heat stress (HS) negatively affects reproductive functions, including prostaglandin (PG) F 2a secretion in the endometrium, and decreases fertility in cattle. In the present study, we examined the effects of elevated temperatures on PG synthesis in oviductal epithelial cells. The epithelial cells obtained from the ampulla and isthmus of the oviduct were incubated at various temperatures (38.5, 39.5, 40.0, and 40.5 8C) for 24 h. In the ampulla, PGE 2 concentration was higher at 40.5 8C than at 38.5 8C, while PGF 2a production was not affected by the temperatures in this range. The expressions of microsomal PGE synthase 1 (PTGES (mPGES1)), cytosolic PGES (PTGES3 (cPGES)), and heat shock protein 90 (HSP90AA1 (HSP90)) mRNAs and proteins were higher at 40.5 8C than at 38.5 8C in the ampullary epithelial cells. Seasonal changes in the expressions of PGES and HSP90AA1 mRNAs in oviductal tissues were also investigated. The expressions of PTGES3 and HSP90AA1 mRNAs were higher in the ampullary tissues in summer than in winter. In summary, elevated temperatures stimulated PGE 2 production in the ampullary oviduct by increasing the expressions of PGESs and HSP90AA1, which can activate cPGES. The overall results suggest that HS upsets PG secretions and reduces oviductal smooth muscle motility, which in turn could decrease gamete/embryo transport through the oviduct.

The global effect of heat on gene expression in cultured bovine mammary epithelial cells

“…The mRNA and protein expression of HSP70 increased after 42°C heat treatment in cultured bovine mammary epithelial cells (Han et al 2014). Heat stress also induced HSP90 expression in bovine BMECs and the bovine oviduct (Kobayashi et al 2013;Deb et al 2014). Furthermore, we also found that heat stress increased the expression of HSP40 (also known as DNAJ proteins) in BMECs.…”

Heat Stress Induced Alterations in Prostaglandins, Ionic and Metabolic Contents of Sheep Endometrial Epithelial Cells In Vitro

“…Our results differed from the report of [21] wherein they suggested that PGE 2 production was increased by elevated temperature in ampullary epithelial cells of cattle oviduct and the increased PGE 2 production could be due to either increases in the expressions of PGESs or increases in the PGES activity. It is concluded that in vitro heat stress altered prostaglandins, ionic and metabolic contents of sheep endometrial epithelial cells.…”

“…Similarly, Kobayashi [21] suggested that elevated temperature did not affect PGE 2 production in isthmic epithelial cells of cattle oviduct.…”

Spatial differences in gene expression in the bovine oviduct

“…After removal of the infundibulum and the uterotubal junction, the oviduct was divided into two parts through the ampullary-isthmic junction, identified where the oviduct diameter first exhibited a marked reduction in size (going from ampulla to isthmus, Fig. 1) (Kobayashi et al 2013). The ampulla and isthmus of both the ipsilateral and contralateral oviduct were flushed with 500 μL PBS to confirm the presence of an unfertilized oocyte or an embryo under a microscope.…”