Identification and characterization of interferon regulatory factors in the ovine uterus /
This research was conducted to determine the cellular and molecular functions of interferon regulatory factors (IRFs) expressed in the ovine endometrium. Interferon tau (IFN[]), which is secreted by conceptus trophectoderm during early pregnancy between Day 10 and 21-25, acts directly on uterine epi...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2002.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=764785831&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | This research was conducted to determine the cellular and molecular functions of interferon regulatory factors (IRFs) expressed in the ovine endometrium. Interferon tau (IFN[]), which is secreted by conceptus trophectoderm during early pregnancy between Day 10 and 21-25, acts directly on uterine epithelium to suppress transcription of estrogen receptor alpha (ERα) and oxytocin receptor (OTR) genes and induces IFN stimulated genes (ISGs) through Janus tyrosine kinase and signal transducers and activators of transcription (JAK-Stat) pathway. Results from the first study indicated that IRF-1, IRF-2, IRF-6 and IRF-9 gene is expressed in the ovine endometrium during early pregnancy. These ovine IRF proteins bind to IFN stimulated response elements (ISRE). Results from the second study indicated that Stat1, Stat2, IRF-1, IRF-9 and IRF-2 gene is regulated in a tissue-type specific manner during the estrous cycle and early pregnancy. Stat1, Stat2, IRF-9 and IRF-1 mRNA and protein was detected and increased in the ovine endometrial stroma and glandular epithelium (GE) during early pregnancy, whereas a potent repressor IRF-2 mRNA and protein was detected and increased in the ovine endometrial luminal epithelium (LE) and superficial GE (sGE). Intrainfusion of IFN[] into cyclic ewe uterus induces or increases Stat1, Stat2, IRF-9 and IRF-1 gene expression, but not IRF-2 expression in the endometrium of cyclic ewes. Transient transfection studies revealed that ovine IRF-2 strongly inhibits transcriptional activity of an ISRE-or IRF-E-driven reporter construct. Results from the third study indicate that the ovine ER?a promoter contains one putative ISRE and four putative IRFEs. IRF-1 and IRF-2 binding could be detected on IRFE and ISRE in the oERα gene promoter. In transfection assay, IRF-2 overexpression inhibits activity of the oERα promoter. Finally, results from the fourth study indicate that early pregnancy and IFN[] induced MHC class I and β₂MG mRNA expression in the uterine endometrium and their expression is restricted in stroma and dGE from early pregnant ewes and IFN[]-treated ewes. Collectively, the lack of these ISGs and ERα in the LE and sGE may be due to the presence of a potent transcriptional repressor IRF-2 constitutively expressed in the LE and sGE, whereas the induction of these ISGs in the stroma and dGE may be due to the presence of common Type I IFN transcriptional activators including Stat1, Stat2, IRF-9 and IRF-1. This event would prevent production of luteolytic pulses of PGF and avoid fetal allograft during pregnancy recognition. |
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| Item Description: | Vita. "Major Subject: Physiology of Reproduction". |
| Physical Description: | xi, 173 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 140-172). |