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Suppression Of Chemically Induced And Spontaneous Mouse Oocyte Activation By Amp-Activated Protein Kinase, Ru Ya, Stephen Downs
Suppression Of Chemically Induced And Spontaneous Mouse Oocyte Activation By Amp-Activated Protein Kinase, Ru Ya, Stephen Downs
Biological Sciences Faculty Research and Publications
Oocyte activation is an important process triggered by fertilization that initiates embryonic development. However, parthenogenetic activation can occur either spontaneously or with chemical treatments. The LT/Sv mouse strain is genetically predisposed to spontaneous activation. LT oocytes have a cell cycle defect and are ovulated at the metaphase I stage instead of metaphase II. A thorough understanding of the female meiosis defects in this strain remains elusive. We have reported that AMP-activated protein kinase (PRKA) has an important role in stimulating meiotic resumption and promoting completion of meiosis I while suppressing premature parthenogenetic activation. Here we show that early activation of …
Role Of Ampk Throughout Meiotic Maturation In The Mouse Oocyte: Evidence For Promotion Of Polar Body Formation And Suppression Of Premature Activation, Stephen Downs, Ru Ya, Christopher C. Davis
Role Of Ampk Throughout Meiotic Maturation In The Mouse Oocyte: Evidence For Promotion Of Polar Body Formation And Suppression Of Premature Activation, Stephen Downs, Ru Ya, Christopher C. Davis
Biological Sciences Faculty Research and Publications
This study was conducted to assess the role of AMPK in regulating meiosis in mouse oocytes from the germinal vesicle stage to metaphase II. Exposure of mouse cumulus cell-enclosed oocytes (CEO) and denuded oocytes (DO) during spontaneous maturation in vitro to AMPK-activating agents resulted in augmentation of the rate and frequency of polar body formation. Inhibitors of AMPK had an opposite, inhibitory effect. In addition, the AMPK inhibitor, compound C (Cmpd C) increased the frequency of oocyte activation. The stimulatory action of the AMPK-activating agent, AICAR, and the inhibitory action of Cmpd C were diminished if exposure was delayed, indicating …
Amp-Activated Protein Kinase Is Involved In Hormone-Induced Mouse Oocyte Meiotic Maturation In Vitro, Jing Chen, Stephen Downs
Amp-Activated Protein Kinase Is Involved In Hormone-Induced Mouse Oocyte Meiotic Maturation In Vitro, Jing Chen, Stephen Downs
Biological Sciences Faculty Research and Publications
We have previously shown that AMP-activated protein kinase (AMPK) can induce the resumption of meiosis in mouse oocytes maintained in meiotic arrest in vitro. The present study was carried out to determine whether AMPK activation is involved in hormone-induced maturation. Follicle-stimulating hormone (FSH) and the EGF-like peptide, amphiregulin (AR), are potent inducers of maturation in cumulus cell-enclosed oocytes (CEO). Within 3 h of FSH treatment, phospho-acetyl CoA carboxylase (ACC) levels were increased in germinal vesicle (GV)-stage oocytes when compared to non-stimulated controls and remained elevated throughout 9 h of culture, indicating AMPK activation. A similar response to AR was observed …
Ampk Regulation Of Mouse Oocyte Meiotic Resumption In Vitro, Jing Chen, Emma R. Hudson, Maggie M. Chi, Aimee S. Chang, Kelle H. Moley, D. Grahame Hardie, Stephen M. Downs
Ampk Regulation Of Mouse Oocyte Meiotic Resumption In Vitro, Jing Chen, Emma R. Hudson, Maggie M. Chi, Aimee S. Chang, Kelle H. Moley, D. Grahame Hardie, Stephen M. Downs
Biological Sciences Faculty Research and Publications
We have previously shown that the adenosine analog 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), an activator of AMP-activated protein kinase (AMPK), stimulates an increase in AMPK activity and induces meiotic resumption in mouse oocytes [Downs, S.M., Hudson, E.R., Hardie, D.G., 2002. A potential role for AMP-activated protein kinase in meiotic induction in mouse oocytes. Dev. Biol, 245, 200–212]. The present study was carried out to better define a causative role for AMPK in oocyte meiotic maturation. When microinjected with a constitutively active AMPK, about 20% of mouse oocytes maintained in meiotic arrest with dibutyryl cAMP (dbcAMP) were stimulated to undergo germinal vesicle breakdown (GVB), …