L-carnitine treatment during oocyte maturation improves in vitro development of cloned pig embryos by influencing intracellular glutathione synthesis and embryonic gene expression
College of Veterinary Medicine, Kangwon National University, Chuncheon, Korea. Theriogenology
(Impact Factor: 1.8).
05/2012; 78(2):235-43. DOI: 10.1016/j.theriogenology.2012.02.027
The objective of this study was to examine the effect of L-carnitine treatment during in vitro maturation (IVM) of immature pig (Sus scrofa) oocytes. Specifically, the effects of L-carnitine treatment on nuclear maturation and oocyte intracellular glutathione (GSH) levels, embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT), and gene expression levels in SCNT pig embryos were determined. During IVM culture, immature oocytes were either treated or not treated with 10 mM L-carnitine. L-carnitine treatment did not improve the nuclear maturation of oocytes but significantly increased intracellular GSH levels, which led to a reduction of reactive oxygen species (ROS) levels in IVM oocytes. Oocytes treated with L-carnitine showed higher (P<0.05) rates of blastocyst formation after PA (39.4% vs. 27.1%) and SCNT (23.2% vs. 14.9%) compared with untreated oocytes. SCNT embryos that were derived from L-carnitine-treated oocytes showed increased (P<0.05) expression levels of DNMT1, PCNA, FGFR2, and POU5F1 mRNA compared with control embryos. Treatment of recipient oocytes with L-carnitine increased (P<0.05) the expression of both BAX and p-Bcl-xl mRNA in SCNT blastocysts. However, the increase was more prominent in BAX than in p-Bcl-xl mRNA. Our results demonstrate that L-carnitine treatment during IVM improves the developmental competence of SCNT embryos. This effect is probably due to increased intracellular GSH synthesis in recipient ooplasts, which reduces ROS levels, and the stimulation of nuclear reprogramming via increased expression of POU5F1 and transcription factors.
Available from: Adel R. Moawad
- "Furthermore, incubation of mouse MII oocytes and embryos with peritoneal fluid collected from women who suffer from endometrioses significantly increases the proportions of oocytes with damaged microtubules and chromosomes and also elevates the level of apoptosis in embryos compared to control groups; however, addition of 0.6 mg/ml LC during culture reverses this effect. In pigs, supplementation of IVM medium with 0.5À0.6 mg/ml LC increases oocyte maturation and cleavage ratesand blastocyst development[45,46]. In cattle, supplementation of embryo culture medium with 1.5À3.0 "
[Show abstract] [Hide abstract]
ABSTRACT: Oocyte cryopreservation is important for assisted reproductive technologies (ART). Although cryopreservation of metaphase II (MII) oocytes has been successfully used, MII oocytes are vulnerable to the damage inflicted by the freezing procedure. Cryopreservation of germinal vesicle (GV) stage oocytes is an alternative choice; however, blastocyst development from GV-oocytes is limited largely due to the need of in vitro maturation (IVM). Herein, we evaluated the effects of L-carnitine (LC) supplementation during vitrification and thawing of mouse GV-oocytes, IVM, and embryo culture on the pre-implantation development after IVF. We first compared the rate of embryonic development from the oocytes collected from three mouse strains, (B6.DBA)F1, (B6.C3H)F1 and B6, followed by IVM and IVF, as well as ovulated oocytes (IVO). Our results demonstrated that the rate of blastocyst development was the highest in the (B6.DBA)F1 strain and the lowest in the B6 strain. We then supplemented the IVM medium with 0.6 mg/ml LC. The rate of blastocyst development improved in the B6 but not in (B6.DBA)F1 strain. Vitrification of GV-oocytes reduced the rate of blastocyst development from both IVM and IVO oocytes in both mouse strains. LC supplementation to the IVM medium alone did not change the percentage of blastocyst development. However, LC supplementation to both vitrification and IVM media significantly improved blastocyst development to the levels comparable with those obtained from vitrified/thawed IVO oocytes in both mouse strains. We conclude that LC supplementation during vitrification is particularly efficient in improving the pre-implantation development from GV-oocytes which have lower developmental competence in culture.
[Show abstract] [Hide abstract]
ABSTRACT: This chapter contains sections titled: Introduction Energy Substrates, In Vivo and In Vitro Limitations of Oocyte Metabolism Assessment Mitochondrial Function in the Oocyte Cattle Oocyte Metabolism Pig Oocyte Metabolism Mouse Oocyte Metabolism Oocyte Metabolism in Other Species Oocyte Metabolism of Fatty Acids Oocyte Metabolism Controls Meiosis: A View across Species Oocyte Metabolism and Redox Balance The Relationship between Oocyte Metabolism and Oocyte Quality Maternal Diet and Disease Can Alter Oocyte Metabolism Oocytes and the Warburg Effect Conclusions References
[Show abstract] [Hide abstract]
ABSTRACT: The objective of this study was to examine the developmental competence of pig oocytes in relation to the size of the perivitelline space (PVS) of oocytes matured in vitro. Immature oocytes were matured in medium 199 or porcine zygote medium (PZM)-3 containing 108 or 61.6 mM NaCl. In vitro-matured (IVM) oocytes were examined for intracellular glutathione (GSH) level; cyclin-dependent kinase 1 (CDK1), proliferating cell nuclear antigen (PCNA), and extracellular signal-regulated kinase 2 (ERK2) mRNA levels; and developmental competence after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT). IVM oocytes with a larger PVS had higher (P < 0.05) levels of intracellular GSH (1.00 pixels/oocyte vs. 0.57 pixels/oocyte) and blastocyst formation (54.3% vs. 37.3%) after PA than oocytes with a smaller PVS. Culturing oocytes for maturation in PZM-3 with reduced (61.6 mM) NaCl increased (P < 0.05) the size of the PVS (6.4 µm vs. 2.8 µm) compared to control oocytes that were matured in normal PZM-3 containing 108 mM NaCl. Moreover, oocytes with a larger PVS showed higher CDK1, PCNA, and ERK2 mRNA and intracellular GSH levels (1.6 pixels/oocyte vs. 1.2 pixels/oocyte) and increased blastocyst formation after PA (52.1% vs. 40.6%) and SCNT (31.8% vs. 18.2%) than control oocytes. Our results demonstrate that pig oocytes with a large PVS have greater developmental competence after PA and SCNT, which is attributed to improved cytoplasmic maturation based on the enhanced GSH level and transcription factor expression. Further, enlargement of the PVS by culturing in low-NaCl medium improves the developmental competence of pig oocytes. Mol. Reprod. Dev. © 2013 Wiley Periodicals, Inc.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.