1998 Fiscal Year Final Research Report Summary
Functional Assay of Prostaglandin F_<2alpha> Receptor for Luteal Cell Apoptosis in Bovine Estrous Cycle
| Project/Area Number |
09680685
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cell biology
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| Research Institution | University of Tsukuba |
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Principal Investigator |
SAKAMOTO Kazuichi Univ.Tsukuba, Inst.Biological Sciences, Associate Professor, 生物科学系, 助教授 (90235169)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Seiji Kansai Medical Univ., Dept.Medical Chemistry, Professor, 医学部, 教授 (80201325)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Prostaglandine F_<2alpha> / receptor / gene expression / coupus luteum / apoptosis / anti-oxydative enzymes / 抗酸化酵素 |
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| Research Abstract |
It is well understood that prostaglandin (PG) F2_<alpha> involved in luteal celI apoptosis in estrous cycle and maintenance of luteal cell function in pregnancy. Our previous data clealy indicated that mRNA expression of PGF2_<alpha> receptor (FP) is critically regulated during the course of maturation and regression of corpus luteum in estrous cycle.
In order to elucidate the regulation mechanism of gene expression of FP in bovine corpus luteum in estrous cycle, we isolated and characterized transcriptional promoter regions of FP gene. One of dual promoters for transcription, so called A region, represented strong promoter activity in primary cells which prepared from bovine corpora lutea in middle estrous cycle. The gel retardation assay and DNasel foot print analysis revealed that specific nuclear proteins could bind to A region (-249--861 ntd upstream of ATG) in estrous cycle dependent manner. In addition, luciferase assay indicated that A region represented strong promoter activity in bovine luteal cells prepared from mid-estrous phase. Futhermore, to identify novel mRNA which specifically expressed in cycling luteal cells and involved in luteal cell apoptosis, differential display assay was performed using total RNAs prepared from different estrous phases. As a result, the cDNA fragment of Mn-type Super Oxyde Dismutase (Mn- SOD) which catalyzes superoxyde reduction, was isolated from mid-phase luteal cDNA pool. To further identify mRNAs which specifically expressed in cycling corpora lutea, RT-PCR and northern blot analysis were performed for Cu/Zn-SOD, GPX and Catalase. Besides the elevated expression of SODs and Catalase during the progress of estrous cycle, GPx was dramatically reduced indicating that excess accumulation of H2O2 could induce luteal cell apoptosis.
As the results of this study, we concluded that strict regulation of gene expression of FP and anti- oxidative enzymes critically controlled luteal cell maintenance and apoptosis in estrous cycle.
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