The present study was undertaken to determine the effect of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) on prostaglandin (PG)F2α and PGE2 secretion as well as cyclooxygenase-2 (COX-2) protein expression in myometrium collected on days 25, 30 and 40 of pregnancy in pigs. Myometrial slices were incubated for 16 h with IL-1β, IL-6 and TNF-α (1 or 10 ng/ml of medium) or two combinations of the three cytokines (1 or 10 ng/ml of each cytokine per combination). We demonstrated the stimulatory effect of IL-1β and IL-6 on PGF2α and PGE2 secretion from myometrium collected on all examined days of pregnancy, excepting of influence of IL-6 on release of PGF2α by tissue from day 30. In turn, TNF-α was able to stimulate only PGE2 secretion by myometrium of 40-day-pregnant gilts. The three cytokines applied in combination augmented release of PGE2 from myometrium collected on days 30 and 40 of pregnancy. Stimulation of PGE2 secretion by cytokines used individually was more frequent than that of PGF2α. Moreover, an enhancement in PGF2α and/or PGE2 release was accompanied by an increase of COX-2 protein expression. Our study shows the ability of cytokines to stimulate PGF2α and PGE2 release by porcine myometrium from the first third of pregnancy. Obtained data suggest that locally PGs produced in myometrium influencing the uterine contraction activity may be important for the maintenance of myometrial quiescence during pregnancy and confirm also that the complex cytokine network is an important regulatory mechanism of PGs production during pregnancy.
High-level expression, purification and characterization of active human C1q and tumour necrosis factor-related protein-1 inEscherichia coli