Carnitine content in the follicular fluid and expression of the enzymes involved in beta oxidation in oocytes and cumulus cells

Montjean, Debbie; Entezami, Frida; Lichtblau, I.; Belloc, S.; Gürgan, Timur; Ménézo, Yves

doi:10.1007/s10815-012-9855-2

Cited by 37 publications

(30 citation statements)

References 19 publications

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“…We can speculate that decreased levels of carnitine and acylcarnitines were associated with improved reproductive potential as a result of their increased utilization via beta-oxidation during oocyte maturation (Varnagy et al, 2013). A similar association was not seen in in a separate study, however, only total carnitine was measured and compared with pregnant and nonpregnant cycles (Montjean et al, 2012). Replication of the association between carnitine (total and free) and the acylcarnitine metabolites with oocyte quality and fertility outcomes, in particular live birth, would be of interest.…”

Section: Carnitine and Fertilitysupporting

confidence: 53%

“…Carnitine is present in human follicular fluid (Dunning and Robker, 2012; Montjean et al, 2012;Valckx et al, 2012;Varnagy et al, 2013;Zhao et al, 2015;Giorgi et al, 2016). While follicular fluid from these studies was sampled following ovulation induction, we can infer from the chemical properties of carnitine and its presence in serum, that carnitine would be present during oocyte maturation in vivo.…”

Section: Carnitine and Fertilitymentioning

confidence: 99%

“…Current evidence suggests that cumulus cells and oocytes do not have the capacity to biosynthesize Lcarnitine from precursor amino acids as they lack the metabolic machinery (Montjean et al, 2012). This study examined human cumulus cells and oocytes at the end of maturation and only mRNA for two of the enzymes in the biosynthesis pathway.…”

Section: Carnitine and Fertilitymentioning

confidence: 99%

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The role of l-carnitine during oocyte in vitro maturation: essential co-factor?

Dunning¹,

Robker²

2017

Anim Reprod

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In vitro maturation (IVM) of oocytes is a promising technology for both the treatment of human infertility and in animal production as a means of improving genetic gain. However, IVM derived oocytes remain inferior to those matured in vivo with reduced developmental potential. The environment in which an oocyte matures in vitro is vastly different to in vivo where maturation takes place within the ovarian follicle. The in vitro environment differs in oxygen concentration, exposure to light, and metabolite composition of culture media vs. follicle fluid, to name a few. Human follicle fluid contains the metabolite Lcarnitine and has shown to be associated with human fertility. L-carnitine has known biological functions as an essential co-factor for beta-oxidation, regulating ATP production from lipids, and as a potent antioxidant. Importantly, it appears that cumulus cells and the oocyte lack the machinery to synthesize L-carnitine de novo. The inability for local production of L-carnitine during IVM and its importance in human fertility warrants investigation of its affects during IVM. The potential to improve oocyte quality by inclusion of L-carnitine in the culture media thus increasing the capacity for betaoxidation and/or antioxidant activity of the culture media is receiving increased attention. This review summarizes studies to date investigating the developmental importance of L-carnitine during IVM and the mechanisms by which improved developmental potential is elicited. Overall, the inclusion of L-carnitine during IVM of several species results in improved oocyte quality with increased development to blastocyst. This is likely due to the antioxidant capacity of L-carnitine and its ability to increase ATP production from intracellular lipid stores.

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Section: Carnitine and Fertilitysupporting

confidence: 53%

Section: Carnitine and Fertilitymentioning

confidence: 99%

Section: Carnitine and Fertilitymentioning

confidence: 99%

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The role of l-carnitine during oocyte in vitro maturation: essential co-factor?

Dunning¹,

Robker²

2017

Anim Reprod

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“…The expression of Cpt1b within the mouse oocyte itself at the MII stage has also been reported (Gentile et al 2004). Recently, gene transcripts involved in b-oxidation, including acyl-CoA synthetases, acyl-CoA dehydrogenases and enoyl-CoA hydratase, have been detected in human oocytes and cumulus cells (Montjean et al 2012). Activity of these enzymes involved in the b-oxidation spiral have also been detected in human oocytes and, interestingly, found to be negatively associated with maternal age (Yazigi et al 1993).…”

Section: Metabolism Of Fatty Acids For the Production Of Atpmentioning

confidence: 95%

“…Furthermore, human oocytes and cumulus cells lack transcripts for the genes involved in the biosynthetic pathway for carnitine production (Montjean et al 2012). In vivo carnitine is most likely to be sourced from the follicular fluid from which levels are abundant and reflect those that found in serum , Montjean et al 2012, Valckx et al 2012; however, in vitro cultures of COCs would lack carnitine and are likely to be deficient in b-oxidation. Thus the potential to improve human oocyte quality during IVM by modulating b-oxidation, including with L-carnitine warrants further investigation.…”

Section: Metabolism Of Fatty Acids For the Production Of Atpmentioning

confidence: 99%

Lipids and oocyte developmental competence: the role of fatty acids and β-oxidation

2014

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Metabolism and ATP levels within the oocyte and adjacent cumulus cells are associated with quality of oocyte and optimal development of a healthy embryo. Lipid metabolism provides a potent source of energy and its importance during oocyte maturation is being increasingly recognised. The triglyceride and fatty acid composition of ovarian follicular fluid has been characterised for many species and is influenced by nutritional status (i.e. dietary fat, fasting, obesity and season) as well as lactation in cows. Lipid in oocytes is a primarily triglyceride of specific fatty acids which differ by species, stored in distinct droplet organelles that re-localise during oocyte maturation. The presence of lipids, particularly saturated vs unsaturated fatty acids, in in vitro maturation systems affects oocyte lipid content as well as developmental competence. Triglycerides are metabolised by lipases that have been localised to cumulus cells as well as oocytes. Fatty acids generated by lipolysis are further metabolised by b-oxidation in mitochondria for the production of ATP. b-oxidation is induced in cumulus-oocyte complexes (COCs) by the LH surge, and pharmacological inhibition of b-oxidation impairs oocyte maturation and embryo development. Promoting b-oxidation with L-carnitine improves embryo development in many species. Thus, fatty acid metabolism in the mammalian COC is regulated by maternal physiological and in vitro environmental conditions; and is important for oocyte developmental competence.

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Metabolite availability as a window to view the early embryo microenvironment in vivo

2017

Molecular Reproduction Devel

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A preimplantation embryo exists independent of blood supply, and relies on energy sources from its in vivo environment (e.g., oviduct and uterine fluid) to sustain its development. The embryos can survive in this aqueous environment because it contains amino acids, proteins, lactate, pyruvate, oxygen, glucose, antioxidants, ions, growth factors, hormones, and phospholipids-albeit the concentration of each component varies by species, stage of the estrous cycle, and anatomical location. The dynamic nature of this environment sustains early development from the one-cell zygote to blastocyst, and is reciprocally influenced by the embryo at each embryonic stage. Focusing on embryo metabolism allowed us to identify how the local environment was deliberately selected to meet the dynamic needs of the preimplantation embryo, and helped reveal approaches to improve the in vitro culture of human embryos for improved implantation rates and pregnancy outcome. | INTRODUCTIONThe basic energy needs-for example, glucose, pyruvate, and lactateof mammalian early embryos were determined for their in vitro culture nearly half a century ago (Biggers & Stern, 1973;Biggers, Whittingham, & Donahue, 1967), with the impact of endogenous fuels, including lipids and amino acids, identified soon thereafter (Chatot, Tasca, & Ziomek, 1990;Hillman & Flynn, 1980;Lane & Gardner, 1998;Quinn & Whittingham, 1982). Considerable progress has been made since these first studies, specifically defining a relatively complete system that accounts for the embryo's changing metabolism, which allowed for better reproducibility of in vitro culture as well as non-invasive assessment of embryo quality (Gardner & Leese, 1986;Gardner & Wale, 2013;Prasad, Tiwari, Koch, & Chaube, 2015;Houghton et al., 2002;Leese, Conaghan, Martin, & Hardy, 1993;Smith & da Rocha, 2012;Thompson, Brown, & Sutton-McDowall, 2016;Vajta, Rienzi, Cobo, & Yovich, 2010). Unfortunately, much of the data on embryo metabolism has come from in vitro studies (AbsalonMedina, Butler, & Gilbert, 2014;Gardner and Harvey, 2015;Leese, 2012Leese, , 2015Menezo, Lichtblau, & Elder, 2013

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Carnitine content in the follicular fluid and expression of the enzymes involved in beta oxidation in oocytes and cumulus cells

Cited by 37 publications

References 19 publications

The role of l-carnitine during oocyte in vitro maturation: essential co-factor?

The role of l-carnitine during oocyte in vitro maturation: essential co-factor?

Lipids and oocyte developmental competence: the role of fatty acids and β-oxidation

Metabolite availability as a window to view the early embryo microenvironment in vivo

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