[Show abstract][Hide abstract] ABSTRACT: C-src is an evolutionarily conserved proto-oncogene that regulates cell proliferation, differentiation and apoptosis. In our previous studies, we have reported that another proto-oncogene, c-erbB2, plays an important role in primordial follicle activation and development. We also found that c-src was expressed in mammalian ovaries, but its functions in primordial follicle activation remain unclear. The objective of this study is to investigate the role and mechanism of c-src during the growth of primordial follicles.
Ovaries from 2-day-old rats were cultured in vitro for 8 days. Three c-src-targeting and one negative control siRNA were designed and used in the present study. PCR, Western blotting and primordial follicle development were assessed for the silencing efficiency of the lentivirus c-src siRNA and its effect on primordial follicle onset. The expression of c-src mRNA and protein in primordial follicle growth were examined using the PCR method and immunohistochemical staining. Furthermore, the MAPK inhibitor PD98059, the PKC inhibitor Calphostin and the PI3K inhibitor LY294002 were used to explore the possible signaling pathways of c-src in primordial folliculogenesis.
The results showed that Src protein was distributed in the ooplasmic membrane and the granulosa cell membrane in the primordial follicles, and c-src expression level increased with the growth of primordial follicle. The c-src -targeting lentivirus siRNAs had a silencing effect on c-src mRNA and protein expression. Eight days after transfection of rat ovaries with c-src siRNA, the GFP fluorescence in frozen ovarian sections was clearly discernible under a fluorescence microscope, and its relative expression level was 5-fold higher than that in the control group. Furthermore, the c-src-targeting lentivirus siRNAs lowered its relative expression level 1.96 times. We also found that the development of cultured primordial follicles was completely arrested after c-src siRNA knockdown of c-src expression. Furthermore, our studies demonstrated that folliculogenesis onset was inhibited by Calphostin, PD98059 or LY294002 treatment,but none of them down-regulated c-src expression. In contrast, the expression levels of p-PKC, p-ERK1/2 and p-PI3K in the follicles were clearly decreased by c-src siRNA transfection. Correspondingly, both Calphostin and LY294002 treatment resulted in a decrease in the p-PKC level in follicles, but no change was observed in the PD98059 group. Finally, LY294002 treatment decreased the p-PI3K expression level in the follicles, but no changes were observed in the PD98059 and Calphostin groups.
C-src plays an important role in regulating primordial follicle activation and growth via the PI3K-PKC- ERK1/2 pathway.
[Show abstract][Hide abstract] ABSTRACT: To explore the role of c-src on the initiation of primordial follicles.
2-days-old female SD rats' ovaries were cultured in Waymouth culture system and were used HE staining and immunohistochemy to observe the number of follicles after 0, 4, 8 days cultured. Use chemically synthesized small interference RNA (siRNA) transfected into ovarian tissue in cultured for RNA interference, and use HE staining and RT-PCR to detect the best siRNA and packaging it by lentiviruses to test the interference effect.
With the increase of culturing days, the nummber of the primordial follicles in ovarian gradually reduced. We packed the best siRNA by lentiviruses to doing RNA interference and found comparing with the blank control group and blank vector group, c-src mRNA of the best interference group were significantly decreased. The total number of primordial follicles was relatively greater and the development of primordial folliculars was inhibited.
c-src plays an important role in primordial follicle development and folliculogenesis initiation.
Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology 11/2011; 27(4):490-4.
[Show abstract][Hide abstract] ABSTRACT: Little is known about the factors that control the initiation of growth of primordial follicles. The objective of the present study was to investigate the effect of c-erbB₂ on the onset of primordial follicle development, and whether c-erbB₂ mediates the effect of epidermal growth factor (EGF) in this process. We synthesized three pairs of siRNAs targeting the c-erbB₂ mRNA and transferred them into the newborn rat ovary cultured in vitro with Metafectene. After siRNAs transfection, the efficiency of siRNAs was tested by examining c-erbB₂ mRNA and protein levels. The level of c-erbB₂ mRNA was reduced by 49.6%, 46.7% and 82.6% respectively after transfecting siRNA1, siRNA2 and siRNA3, and the level of ErbB₂ protein also reduced remarkably after siRNA3 transfection. c-erbB₂ siRNA3 significantly inhibited the primordial follicle initiation and development; EGF augmented primordial follicles formation, but the effect was abolished by c-erbB₂ siRNA3. All of these results suggest that c-erbB₂ plays an important role in primordial follicle development and folliculogenesis initiation, and mediates the effect of EGF on primordial follicle development.
Sheng li xue bao: [Acta physiologica Sinica] 10/2009; 61(5):424-30.