title: Let-7g induces granulosa cell apoptosis by targeting MAP3K1 in the porcine ovary.
abstract: Follicular atresia mainly results from apoptosis of granulosa cells (GCs). Our previous microRNA array data indicated that the miRNA let-7g level increases significantly during porcine ovary follicular atresia. It is uncertain if GCs apoptosis is mediated by microRNA let-7g. In this study, the expression levels of the apoptosis-associated genes CASP3, BAX and BIM were significantly upregulated when let-7g mimic was transfected into porcine GCs, and the anti-apoptotic genes BCL-2 and MCL-1 were significantly downregulated. The apoptosis rate was measured by flow cytometry, and our results indicated that let-7g significantly enhanced GCs apoptosis. In further studies, we found that overexpression of let-7g induced the expression of FoxO1 in GCs and led to nuclear accumulation of dephosphorylated FoxO1. In addition, the effect of let-7g on FoxO1 expression and dephosphorylation resulted from repression of the expression of the MAP3K1 gene in porcine GCs. The site on MAP3K1 mRNA targeted by let-7g was confirmed by luciferase reporter assay. The anti-apoptotic effect of MAP3K1 was validated by silencing MAP3K1 using small interfering RNA technology. In conclusion, our data indicate that let-7g induces porcine GCs apoptosis by inhibiting the MAP3K1 gene, which promotes FoxO1 expression and dephosphorylation with nuclear accumulation.
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Rui
authors: R
authors: Cao
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Wangjun
authors: W
authors: Wu
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Xiaolong
authors: X
authors: Zhou
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Kaiqing
authors: K
authors: Liu
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Bojiang
authors: B
authors: Li
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Xianju
authors: X
authors: Huang
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Yu
authors: Y
authors: Zhang
authors: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China. Electronic address: liuhonglin@njau.edu.cn.
authors: Honglin
authors: H
authors: Liu
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D000072224:Bcl-2-Like Protein 11; D001665:Binding Sites; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D005260:Female; D005496:Follicular Atresia / Q000235:genetics* / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006107:Granulosa Cells / Q000166:cytology / Q000378:metabolism*; D048728:MAP Kinase Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D064549:Myeloid Cell Leukemia Sequence 1 Protein / Q000235:genetics / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D061251:Primary Cell Culture; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013552:Swine; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; D051858:Forkhead Transcription Factors; D008565:Membrane Proteins; D035683:MicroRNAs; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D016376:Oligonucleotides, Antisense; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051028:bcl-2-Associated X Protein; D048728:MAP Kinase Kinase Kinase 1; D053148:Caspase 3
keywords: Apoptosis; FoxO1; Granulosa cell; Let-7g; MAP3K1