Relationship between quantity of IFNT estimated by IFN-stimulated gene expression in peripheral blood mononuclear cells and bovine embryonic mortality after AI or ET

Abstract

BackgroundInterferon tau (IFNT), which is secreted into the uterine cavity during the maternal recognition period (MRP), is a key factor for establishment of pregnancy. The present study aims to clarify the relationship between the ability of a bovine conceptus to produce IFNT during the MRP and the conceptus's ability to establish pregnancy.MethodsIn the first experiment, IFNT (0, 500, or 1000 micrograms) was administered into the uterine horn ipsilateral to the CL 16 or 17 d after standing estrus, and mRNA levels of IFN-stimulated gene 15-kDa protein (ISG15) and Mx2 in peripheral blood mononuclear cells (PBMCs) were determined. In the second experiment, we investigated ISG15 mRNA expression in PBMCs during the MRP in cattle after either artificial insemination (AI) or embryo transfer (ET).ResultsIntrauterine administration of IFNT stimulated ISG15 and Mx2 gene expressions in PBMCs in cattle, and there was a positive correlation between the expressions of peripheral markers and the quantity of IFNT administered. In pregnant and normal interestrous interval (< 25 d) cattle (nIEI cattle), expression levels of the ISG15 gene showed similar patterns after AI and ET, and ISG15 mRNA expression was increased in pregnant cattle but unchanged in nIEI cattle. In contrast, ISG15 gene expression in extended interestrous interval (greater than or equal to 25 d) cattle (eIEI cattle) differed after ET compared with AI. In eIEI cattle after ET, ISG15 gene expression increased, such that the value on day 18 was intermediate between those of pregnant and nIEI cattle. In eIEI cattle after AI, ISG15 gene expression did not increase throughout the observation period.ConclusionsThe results of the current study indicate that the quantity of conceptus-derived IFNT can be estimated by measuring ISG15 mRNA levels in PBMCs from cattle. Using this approach, we demonstrate that ISG15 gene expression during the MRP in eIEI cattle differed after ET compared with AI. In addition, the modest increase in ISG15 gene expression in eIEI cattle after ET suggests that late embryo losses were due to delayed or insufficient growth of the conceptus during the MRP in cattle.

Interferon Stimulated Genes (Isgs): Novel Pregnancy Specific Biomarker In Buffaloes (Bubalus bubalis

“…The IFNT intensifies the MX1 and MX2 expression in PBMCs of ruminants and could able to signal MRP 23 …”

“…It has been indicated that, IFNT goes from uterine vein to systemic circulation and induces the ISGs expression in peripheral blood mononuclear cells (PBMCs) 19,20 . It is well known that, ISGs expression was not only induce maternal recognition of pregnancy (MRP) but also helpful for early detection of pregnancy in ruminants [21][22][23] . Likewise, administration of IFNT to uterine endometrium up surged ISG15 expression in PBMCs of ruminants 23 .…”

“…It is well known that, ISGs expression was not only induce maternal recognition of pregnancy (MRP) but also helpful for early detection of pregnancy in ruminants [21][22][23] . Likewise, administration of IFNT to uterine endometrium up surged ISG15 expression in PBMCs of ruminants 23 .…”

Exogenous hormonal manipulation to increase reproductive efficiency in dairy cows

“…It is unclear why supplemental progesterone did not result in further stimulation of mRNA expression of ISG in leukocytes of pregnant cows compared with untreated controls. It was thought that pregnant cows would have advanced conceptus development with supplemental progesterone (CARTER et al, 2008), and the latter were expected to have an earlier and more robust increment in expression of ISG because of increased IFN-τ in utero (MATSUYAMA et al, 2012). The mRNA abundance in blood leukocytes of the two genes investigated in the present study were previously described to be associated with improved conceptus development and increased fertility in lactating dairy cows .…”

“…Production of IFN-τ by the conceptus induces IFN-stimulated genes (ISG) in the endometrium such as myxovirus (influenza virus) resistance 1 (Mx1) and receptor transporter protein 4 (RTP4; HICKS et al, 2003;GIFFORD et al, 2008). Blood leukocytes harvested on d 16 or 19 after AI had increased expression of the ISG ubiquitin-like IFNstimulated gene 15-kDa protein (IGS15), Mx1, Mx2, and RTP4 (GIFFORD et al, 2007;, and leukocyte mRNA for ISG was correlated with the amount of IFN-τ in the uterus (MATSUYAMA et al, 2012). Interestingly, stimulation of conceptus development during pre-and peri-implantation resulted in increased expression of ISG in blood leukocytes and increased P/AI in lactating dairy cows .…”