scholarly journals The effect of pregnancy on the expression of uterine oxytocin, oestrogen and progesterone receptors during early pregnancy in the cow

1999 ◽  
Vol 160 (1) ◽  
pp. 21-33 ◽  
Author(s):  
RS Robinson ◽  
GE Mann ◽  
GE Lamming ◽  
DC Wathes

The expression of oxytocin receptor (OTR) in the uterine endometrium plays an important role in the initiation of luteolysis. During early pregnancy, the conceptus secretes interferon tau (IFN|gt) which inhibits OTR up-regulation and luteolysis. In this study, uterine horn cross sections were collected on day 16 from 15 pregnant cows (PREG), 9 uninseminated controls and 5 inseminated cows with no embryo present. The latter two groups had similar results and were combined to form a single non-pregnant (NP) group. The animals were given an oxytocin challenge shortly before tissue collection to assess prostaglandin F2alpha (PGF2alpha) release through the measurement of the metabolite 13,14-dihydro-15-keto PGF2alpha (PGFM). The mRNAs for OTR, oestrogen receptor (ER) and progesterone receptor (PR) were localised by in situ hybridisation. The results were quantified by optical density (OD) measurements from autoradiographs using image analysis. OTR protein was measured by autoradiography with iodinated oxytocin antagonist and ER and PR protein was detected by immunocytochemistry. The release of PGFM after the oxytocin challenge was significantly higher in the 14 NP cows (187%+/-15%) compared with the PREG group (131%+/-11%) (P<0.01). Low concentrations of OTR mRNA were localised to the luminal epithelium (LE) in 6 out of the 14 NP cows, of which 2 also expressed OTR protein, while OTR mRNA and protein were undetectable in all the pregnant animals. These results indicated that the sampling time coincided with the onset of the luteolytic mechanism in the NP cows. On day 16 ER mRNA was detectable in both the LE and glands of both PREG and NP animals. There were no differences in either ER mRNA or protein between NP and PREG samples. PR mRNA was moderately expressed in the caruncular stroma, with lower levels in the dense caruncular-like stroma and glands. There were no differences between PREG and NP animals. The expression of PR mRNA and protein in the deep glands was variable between animals. These results suggested that, in cows, the presence of an embryo suppressed the expression of OTR, but had no effect on the expression of the transcriptionally regulated ER on day 16.

2001 ◽  
Vol 26 (2) ◽  
pp. 289-295 ◽  
Author(s):  
R.S. Robinson ◽  
G.E. Mann ◽  
G.E. Lamming ◽  
D.C. Wathes

AbstractIn the cow, the embryo during the first three weeks of pregnancy is free living in the uterine lumen and is dependent on the maternal glandular secretions for its nutritional support. If the environment is appropriate, the embryo will develop sufficiently to prevent luteolysis. The aim of this study was to investigate the regulation of factors involved in embryonic-endometrial interactions during early pregnancy. Uterine horn sections were collected from 17 pregnant (PREG), 9 inseminated but no embryo present and 10 uninseminated cyclic control cows on days 12, 14, 16 and 18 after natural oestrus. The latter two groups were combined to form a single non-pregnant (NP) group. Trophoblast sections were also collected from the day 14, 16 and 18 embryos. The mRNA for interferon tau (IFNτ), oxytocin receptor (OTR), oestrogen receptor a (ER), prostaglandin G/H synthase -2 (PGHS-2), insulin-like growth factor (IGF) -I and IGF binding protein -1 (IGFBP-1) was determined by in situ hybridisation using 45 mer oligonucleotide probes end-labelled with35 S. The optical density (OD) readings were measured from the resulting autoradiographs. The expression of IFNτ mRNA in the trophodectoderm did not vary with embryo age. The expression of OTR mRNA in the luminal epithelium was first detectable on day 14 in 2 out of 5 NP cows and increased thereafter. Conversely, OTR mRNA was undetectable in all PREG cows except for one day 18 cow. In the NP cows, the first significant increase in ER mRNA concentrations in the luminal epithelium was observed on day 16. The pregnancy had no effect on ER mRNA concentrations in the luminal epithelium on days 12 and 14, but was significantly reduced on day 16 and was undetectable by day 18. On day 18, PGHS-2 mRNA was detectable in the luminal epithelium of all cows, but was unaffected by pregnancy status. The expression of IGF-I mRNA in the subepithelial stroma was maintained from days 12 to 18, but was reduced in the day 18 NP cows. IGFBP-1 mRNA concentrations in the luminal epithelium peaked on day 14 in both NP and PREG cows. Thereafter, concentrations declined in the NP group but were maintained in the PREG animals. In conclusion, the suppression of OTR mRNA expression by the embryo does not appear to require the prior suppression of ER mRNA. The continued expression of IGF-I and IGFBP-1 mRNA is likely to play an important role in the establishment of early pregnancy in the cow.


2000 ◽  
Vol 165 (2) ◽  
pp. 231-243 ◽  
Author(s):  
RS Robinson ◽  
GE Mann ◽  
TS Gadd ◽  
GE Lamming ◽  
DC Wathes

The IGF system is expressed in the uterus during the oestrous cycle and early pregnancy and is likely to play an important role in regulating the development of the embryo and uterus. The IGF peptides (IGF-I and -II) mediate their effects through the type 1 IGF receptor (IGF-1R), while the IGF-binding proteins (IGFBP-1 to -6) modulate their interaction with the receptor. In this study, the expression of the IGF system in the bovine uterus was determined throughout the oestrous cycle and on day 16 of pregnancy. Endometrial biopsy samples were collected from four cows over three cycles such that there were samples for every 2 days from day 0 (oestrus) to day 14 and then every day until day 21. To assess the effect of pregnancy, uterine horn cross-sections were collected on day 16 from 15 pregnant (PREG), five inseminated non-pregnant (INP) and nine uninseminated cyclic controls (CONT). The expression of mRNA for the IGFs, IGF-1R and IGFBP-1 to -5 was determined by in situ hybridisation and the results were quantified by measuring the optical density units from autoradiographs. The main region of IGF-I mRNA expression was the sub-epithelial stroma underlying the luminal epithelium. The expression of IGF-I mRNA was highest at oestrus and lowest during the early and late luteal phases. On day 16, IGF-I mRNA levels were low in all groups, with pregnancy having no effect on the IGF-I mRNA concentrations. The strongest expression of IGF-II mRNA was in the caruncular stroma, with pregnancy having no significant effect in this region. IGF-1R mRNA was also present in the caruncles and was strongly expressed in all epithelial cells both throughout the oestrous cycle and during early pregnancy. The expression of IGFBP-1 mRNA was confined to the luminal epithelium, with the strongest expression seen on day 14 of the cycle. On day 16 the expression of IGFBP-1 mRNA was higher in the PREG group compared with the CONT group. The expression of IGFBP-2 mRNA was localised to the sub-epithelial stroma with more INP than PREG cows showing detectable levels of IGFBP-2. The strongest expression of IGFBP-3 mRNA was in the caruncular stroma; expression in the endometrial stroma was similarly decreased during early pregnancy. IGFBP-5 mRNA was mainly expressed in the inner ring of myometrium and was not affected by pregnancy on day 16. In conclusion, these results show that many components of the uterine IGF system are differentially regulated during the oestrous cycle and early pregnancy and suggest that modulation of the IGF system may influence uterine activity during this period.


2006 ◽  
Vol 18 (3) ◽  
pp. 339 ◽  
Author(s):  
Ralph Rühl ◽  
Britta Fritzsche ◽  
Julien Vermot ◽  
Karen Niederreither ◽  
Ulrike Neumann ◽  
...  

The active metabolite of vitamin A, retinoic acid (RA), plays an important role in the female reproductive system. The synthesis of RA is tightly regulated by the activity of retinaldehyde dehydrogenases (Raldh). Among these, Raldh1 and Raldh2 exhibit specific temporal and spatial expression patterns in the mouse uterus, both during the oestrous cycle and early pregnancy. In the present study, we have assessed whether oestradiol and progesterone directly influence the uterine expression of Raldh1 and Raldh2 in ovariectomised mice. We investigated the effect of gestagen (promegestone 0.3 mg kg−1 bodyweight), oestrogen (oestradiol 3 µg kg−1 bodyweight) and their combination on the uterine expression of Raldh2. Expression was analysed using in situ hybridisation and quantified using real-time detection reverse transcription–polymerase chain reaction. The results show that the expression of Raldh2 is rapidly (within 1–4 h) induced in stromal cells by oestrogen, but not by gestagen, treatment, whereas combined oestrogen + gestagen treatment leads to a more prolonged (48 h) response. In contrast, oestrogen, but not progesterone, treatment downregulates (within 4–24 h) Raldh1 expression in the uterine glandular epithelium. We conclude that the uterine RA concentrations are regulated by oestrogens via an effect on the expression of the Raldh synthesising enzymes. Such a regulation is consistent with the natural fluctuations of Raldh expression during the oestrous cycle, early pregnancy and blastocyst implantation.


Reproduction ◽  
2009 ◽  
Vol 138 (5) ◽  
pp. 813-825 ◽  
Author(s):  
Hyo Won Ahn ◽  
Jennifer L Farmer ◽  
Fuller W Bazer ◽  
Thomas E Spencer

During early pregnancy in ruminants, progesterone (P4) and interferon tau (IFNT) act on the endometrium to regulate genes hypothesized to be important for conceptus development and implantation. The present study was conducted to verify several candidate genes (actin α-2, smooth muscle, aorta (ACTA2), collagen, type III, α-1 (COL3A1), periostin (POSTN), secreted protein acidic cysteine-rich (SPARC), S100 calcium-binding protein A2 (S100A2),STAT5Aand transgelin (TAGLN)) regulated by pregnancy, P4, and/or IFNT in the endometrium determined using a custom ovine cDNA array.S100A2mRNA was detected primarily in endometrial epithelia and conceptuses.S100A2mRNA increased in endometrial epithelia from days 10 to 16 in cyclic ewes and from days 10 to 14 in pregnant ewes and declined thereafter. The abundance ofS100A2mRNA was less in endometrial luminal epithelium of IFNT-infused ewes receiving P4. Expression ofCOL3A1, SPARC, ACTA2, andTAGLNwas independent of pregnancy, P4, or IFNT.POSTNmRNA was detected primarily in compact stroma of intercaruncular and caruncular endometria, but not in the conceptus. EndometrialPOSTNmRNA increased between days 12 and 14 in pregnant but not cyclic ewes, andPOSTNmRNA was more abundant in uterine stroma of ewes treated with P4. POSTN protein was detected in uterine flushings of pregnant ewes and found to mediate attachment and stimulate migration of ovine trophectoderm cellsin vitro. These results support the ideas that POSTN and S100A2 are regulated by P4and IFNT respectively, and that POSTN is involved in conceptus elongation during early pregnancy.


2001 ◽  
Vol 169 (2) ◽  
pp. 291-298 ◽  
Author(s):  
AI Turner ◽  
AJ Tilbrook ◽  
IJ Clarke ◽  
CJ Scott

We tested the hypotheses that progesterone enhances the negative feedback actions of testosterone in rams and that this occurs through actions at the hypothalamus. In the first part of this study, blood samples were collected every 10 min for 12 h before and after 7 days of treatment (i.m.) of castrated Romney Marsh rams (n=5 per group) with vehicle, progesterone (4 mg/12 h), testosterone (4 mg/12 h) or a combination of progesterone (4 mg/12 h) and testosterone (4 mg/12 h). In the second part of this study the brains of four gonad-intact Romney Marsh rams were collected, the hypothalamus was sectioned and in situ hybridisation of mRNA for progesterone receptors conducted. After 7 days of treatment with vehicle or progesterone or testosterone alone, there were no changes in the secretion of LH. In contrast, treatment with a combination of progesterone and testosterone resulted in a significant (P<0.01, repeated measures ANOVA) decrease in mean plasma concentrations of LH, the number of LH pulses per hour and the pre-LH pulse nadir and a significant (P<0.01) increase in the inter-LH pulse interval. We found cells containing mRNA for progesterone receptors throughout the hypothalamus, including the preoptic area (where most GnRH neurons are located in sheep), the periventricular, ventromedial and arcuate nuclei and the bed nucleus of the stria terminalis. This study shows that progesterone is capable of acting centrally with testosterone to suppress the secretion of LH in castrated rams and that cells containing mRNA for progesterone receptors are located in the hypothalamus of rams in the vicinity of GnRH neurons.


Reproduction ◽  
2000 ◽  
pp. 387-395 ◽  
Author(s):  
KJ Demmers ◽  
HN Jabbour ◽  
DW Deakin ◽  
AP Flint

The role of interferon in early pregnancy in red deer was investigated by (a) measuring production of interferon by the conceptus, (b) testing the anti-luteolytic effect of recombinant interferon-tau in non-pregnant hinds, and (c) treatment of hinds with interferon after asynchronous embryo transfer. Blastocysts were collected from 34 hinds by uterine flushing 14 (n = 2), 16 (n = 2), 18 (n = 8), 20 (n = 13) or 22 (n = 9) days after synchronization of oestrus with progesterone withdrawal. Interferon anti-viral activity was detectable in uterine flushings from day 16 to day 22, and increased with duration of gestation (P < 0.01) and developmental stage (P < 0.01). When interferon-tau was administered daily between day 14 and day 20 to non-pregnant hinds to mimic natural blastocyst production, luteolysis was delayed by a dose of 0.2 mg day(-1) (27.3 +/- 1.3 days after synchronization, n = 4 versus 21 +/- 0 days in control hinds, n = 3; P < 0.05). Interferon-tau was administered to hinds after asynchronous embryo transfer to determine whether it protects the conceptus against early pregnancy loss. Embryos (n = 24) collected on day 6 from naturally mated, superovulated donors (n = 15) were transferred into synchronized recipients on day 10 or day 11. Interferon-tau treatment (0.2 mg daily from day 14 to 20) increased calving rate from 0 to 64% in all recipients (0/11 versus 7/11, P < 0.005), and from 0 to 67% in day 10 recipients (0/8 versus 6/9, P < 0.01). The increased success rate of asynchronous embryo transfer after interferon-tau treatment in cervids may be of benefit where mismatched embryo-maternal signalling leads to failure in the establishment of pregnancy.


1999 ◽  
Vol 39 (6) ◽  
pp. 13-20 ◽  
Author(s):  
Philip L. Bond ◽  
Jürg Keller ◽  
Linda L. Blackall

Culturing bacteria from activated sludge with enhanced biological phosphorus removal (EBPR) has strongly implicated Acinetobacter with the process. However, using fluorescent in-situ hybridisation (FISH) probing to analyse microbial populations, we have shown evidence opposing this widespread belief. We describe the phosphorus (P) removing performance and microbial population analyses of sludges obtained in a laboratory scale EBPR reactor. Two sludges with extremely high P removing capabilities were examined, the P content of these sludges was 8.6% (P sludge) and 12.3% (S sludge) of the MLSS. Identification of bacteria using FISH probing indicated both sludges were dominated by microbes from the beta proteobacteria and high mol% G+C Gram positive bacteria. Acinetobacter could make up only a small proportion of the cells in these sludges. Sludge with extremely poor P removal (P content of 1.5%, referred to as T sludge) was then generated by reducing the P in the influent. Bacteria resembling the G-bacteria became abundant in this sludge and these were identified using FISH probing. The anaerobic transformations of the T and P sludges correlated well with that of the non-EBPR and EBPR biological models respectively, indicating that bacteria in the T sludge have the potential to inhibit P removal in EBPR systems.


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