Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1983454 | The International Journal of Biochemistry & Cell Biology | 2015 | 10 Pages |
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.
Keywords
PBSNF-kappa-BMAP3K1Let-7gc-Jun NH2-terminal kinaseGCsBcl2TBSTRIPADAPIERKFOXO1miRNAsJnk3′ UTRBSAB-cell CLL/lymphoma 2Mcl1p38-MAPKradio-immunoprecipitation assaybovine serum albuminBaxmyeloid cell leukemia sequence 1MutantApoptosisKEGG یا Kyoto Encyclopedia of Genes and Genomes Kyoto Encyclopedia of Genes and Genomesgranulosa cellgranulosa cellsFasLNuclear factor-kappa BPhosphate buffered salinephosphatase and tensin homologTRAILtumor necrosis factor-related apoptosis-inducing ligandBIM3′-untranslated regionsGene ontologyBCL2-associated X proteinp38 mitogen-activated protein kinasesExtracellular signal-regulated protein kinasePropidium iodidePten
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Authors
Rui Cao, Wangjun Wu, Xiaolong Zhou, Kaiqing Liu, Bojiang Li, Xianju Huang, Yu Zhang, Honglin Liu,