1. JNK signaling regulates E-cadherin junctions in germline cysts and determines primordial follicle formation in mice.
- Author
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Niu W, Wang Y, Wang Z, Xin Q, Wang Y, Feng L, Zhao L, Wen J, Zhang H, Wang C, and Xia G
- Subjects
- Animals, Female, Gene Knockdown Techniques, JNK Mitogen-Activated Protein Kinases antagonists & inhibitors, Mice, Proteolysis, Proto-Oncogene Proteins c-mdm2 metabolism, Wnt4 Protein metabolism, Cadherins metabolism, Germ Cells metabolism, JNK Mitogen-Activated Protein Kinases metabolism, MAP Kinase Signaling System, Organogenesis, Ovarian Follicle metabolism
- Abstract
Physiologically, the size of the primordial follicle pool determines the reproductive lifespan of female mammals, while its establishment largely depends on a process of germline cyst breakdown during the perinatal period. The mechanisms regulating this process are poorly understood. Here we demonstrate that c-Jun amino-terminal kinase (JNK) signaling is crucial for germline cyst breakdown and primordial follicle formation. JNK was specifically localized in oocytes and its activity increased as germline cyst breakdown progressed. Importantly, disruption of JNK signaling with a specific inhibitor (SP600125) or knockdown technology (Lenti-JNK-shRNAs) resulted in significantly suppressed cyst breakdown and primordial follicle formation in cultured mouse ovaries. Our results show that E-cadherin is intensely expressed in germline cysts, and that its decline is necessary for oocyte release from the cyst. However, inhibition of JNK signaling leads to aberrantly enhanced localization of E-cadherin at oocyte-oocyte contact sites. WNT4 expression is upregulated after SP600125 treatment. Additionally, similar to the effect of SP600125 treatment, WNT4 overexpression delays cyst breakdown and is accompanied by abnormal E-cadherin expression patterns. In conclusion, our results suggest that JNK signaling, which is inversely correlated with WNT4, plays an important role in perinatal germline cyst breakdown and primordial follicle formation by regulating E-cadherin junctions between oocytes in mouse ovaries., (© 2016. Published by The Company of Biologists Ltd.)
- Published
- 2016
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