Secretion of Bovine Uterine Proteins in Response to Type I Interferons1

Abstract

Bovine interferon-tau (bIFN-tau) is secreted by the developing conceptus and initiates antiluteolytic events by interacting with uterine membrane receptors. We have identified three endometrial proteins (approximately 8, 16, and 28 kDa; P8, P16, and P28; respectively) that are secreted in response to recombinant (r) bIFN-tau. The objective of this study was to determine whether or not secretion of these proteins was a unique response to IFN-tau during early pregnancy. Three experiments were designed to examine secretion of endometrial proteins as a function of time in culture (0, 3, 6, 12, 18, 24 h), stage of the estrous cycle and pregnancy (Days 15, 18, 0/21), and dose of Type I IFN (0, 0.5, 5, and 25 nM; rbIFN-tau, rbIFN-alpha, and roIFN-tau). Endometrium was cultured for times specified with L-[3H]leusine to generate radiolabeled proteins. Secreted proteins were quantitated by using one-dimensional (1D)-PAGE, fluorography, and densitometry. Secretion of P8, P16, and P28 increased over time (p < 0.0001) in culture and in response to 25 nM rbIFN-tau (p < 0.05). Secretion of P8 in response to rbIFN-tau was higher (p < 0.05). Secretion of P8 in response to rbIFN-tau was higher (p < 0.0005) in endometrium collected from pregnant than nonpregnant heifers, but did not differ across the days examined. Although secretion of P8 was higher (p < 0.0001) in the presence than in the absence of rbIFN-tau, it was not affected by rbIFN-alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Localization of Ubiquitin and Ubiquitin Cross-Reactive Protein in Human and Baboon Endometrium and Decidua during the Menstrual Cycle and Early Pregnancy1

“…The appearance of anti-UCRP immunoreactivity in decidual cells at the beginning of pregnancy indicates that it may play an important role in the establishment of the conceptus. An anti-UCRP-immunoreactive polypeptide of 16 kDa, which appears to be free UCRP [13], is found in uterine washes of pregnant, but not nonpregnant, cows and is one of a small number of proteins released from the endometrium in response to IFN [21], which suggests that the protein is specifically secreted from uterine tissue. The functional significance of these findings is not clear, although the secretion of IFN-␥ by monocytes in response to UCRP has previously been reported [37] and the protein therefore may play a vital role in coordination of the complex network of IFNs during the initiation of bovine pregnancy.…”

“…It is possible, therefore, that the ubiquitin system could be involved in the extensive uterine remodeling during the menstrual cycle and pregnancy. Recent work by Hansen and coworkers has shown that UCRP is one of the proteins secreted by the bovine uterus in response to type 1 interferons [21]. The bovine conceptus produces IFNduring the first 30 days of pregnancy prior to placental attachment, during which time it is thought to maintain the pregnant state [22].…”

Interferon-τ Induces Degradation of Prostaglandin H Synthase-2 Messenger RNA in Bovine Endometrial Cells Through a Transcription-Dependent Mechanism1

“…Expression of IRF-1 protein was evident at 1 h after IFN-treatment in BEND cells [23]. The IFNinduced gene transcription in bovine and ovine uteri [47][48][49][50][51]. One product of IFN--induced transcription is ISG17 [52].…”

<b>Interferon-tau Polymorphisms and Their Potential Functions in Ruminants</b>

“…Such findings do not dismiss the possibility that IFN-ô contains a unique ability to act on other aspects of pregnancy recognition, such as modulating the local immune system or controlling uterine protein production. In fact, uterine secretions are slightly different following treatment with IFN-ô and IFN-á (Naivar et al, 1995). The production of at least one uterine protein, granulocyte chemotactic protein-2, is stimulated by IFN-ô but not by IFN-á in bovine endometrium (Staggs et al, 1998).…”