biostudies-literatureUnknown9(10)Iwamune MThe 78-kilodalton glucose-regulated protein (GRP78) is a molecular chaperone that assists in protein assembly, folding, and translocation. Recently, our laboratory reported that GRP78 regulates the expression of luteinizing hormone-human chorionic gonadotropin receptor (LHR) in the early stage of corpus luteum formation. In this study, we investigated whether microRNAs (miRNAs), which post-transcriptionally regulate mRNA, are involved in the regulation mechanism of GRP78 in the ovary. A miRNA microarray was performed to analyze the overall miRNA expression profile, and the results indicated that 44 miRNAs were expressed highly after ovulation was induced. The results from a bio-informative database analysis and in vitro granulosa cell culture studies led us to focus on rno-miR-376a for further analysis. In both in vivo and in vitro studies, rno-miR-376a levels increased 12 h after human chorionic gonadotropin (hCG) administration. To elucidate whether rno-miR-376a induced mRNA destabilization or translational repression of GRP78, rno-miR-376a was transfected into cultured granulosa cells, resulting in decreased GPR78 protein levels without an alteration in GRP78 mRNA levels. To confirm that rno-miR-376a binds to GRP78 mRNA, we cloned the 3'-end of GRP78 mRNA (nucleotides 2439-2459) into a reporter vector that contained a Renilla luciferase coding region upstream of the cloning site. The luciferase assays revealed that rno-miR-376a bound to the 3'-end of GRP78 mRNA. From these data, we conclude that rno-miR-376a potentially negatively regulates GRP78 protein expression through translational repression at an early stage transition from the follicular phase to luteinization.PloS onee108997https://www.ebi.ac.uk/biostudies/studies/S-EPMC4184830biostudies-literatureMicroRNA-376a regulates 78-kilodalton glucose-regulated protein expression in rat granulosa cells.PMC4184830Kitahara YNakamura KMinegishi TIwamune MfalseMicroRNA-376a regulates 78-kilodalton glucose-regulated protein expression in rat granulosa cells.The 78-kilodalton glucose-regulated protein (GRP78) is a molecular chaperone that assists in protein assembly, folding, and translocation. Recently, our laboratory reported that GRP78 regulates the expression of luteinizing hormone-human chorionic gonadotropin receptor (LHR) in the early stage of corpus luteum formation. In this study, we investigated whether microRNAs (miRNAs), which post-transcriptionally regulate mRNA, are involved in the regulation mechanism of GRP78 in the ovary. A miRNA microarray was performed to analyze the overall miRNA expression profile, and the results indicated that 44 miRNAs were expressed highly after ovulation was induced. The results from a bio-informative database analysis and in vitro granulosa cell culture studies led us to focus on rno-miR-376a for further analysis. In both in vivo and in vitro studies, rno-miR-376a levels increased 12 h after human chorionic gonadotropin (hCG) administration. To elucidate whether rno-miR-376a induced mRNA destabilization or translational repression of GRP78, rno-miR-376a was transfected into cultured granulosa cells, resulting in decreased GPR78 protein levels without an alteration in GRP78 mRNA levels. To confirm that rno-miR-376a binds to GRP78 mRNA, we cloned the 3'-end of GRP78 mRNA (nucleotides 2439-2459) into a reporter vector that contained a Renilla luciferase coding region upstream of the cloning site. The luciferase assays revealed that rno-miR-376a bound to the 3'-end of GRP78 mRNA. From these data, we conclude that rno-miR-376a potentially negatively regulates GRP78 protein expression through translational repression at an early stage transition from the follicular phase to luteinization.2014-01-01T00:00:00Z20142024-12-04T02:03:04.851Z2019-03-26T23:21:42ZS-EPMC41848302527984110.1371/journal.pone.0108997