Reduced GLUT1 expression in Igf1–/– null oocytes and follicles

Zhou, Jian; Bievre, Marsha; Bondy, CA

doi:10.1054/ghir.2000.0147

Cited by 54 publications

(37 citation statements)

References 12 publications

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“…The effect of insulin treatment on other enzymes in the insulin signaling pathway in oocytes or cumulus cells is unknown [102]. The IGF-1 knockout mice have decreased granulosa cell proliferation and decreased GLUT1 [89,104], similar to results observed in blastocysts following PI3K inhibition [98]. Feeding mice a high fat diet for 16 weeks leads to weight gain and hyperinsulinemia, poor oocyte quality, and impaired ovulation [105].…”

Section: Insulinmentioning

confidence: 81%

“…There are reports of GLUT4 in granulosa cells of the mouse by immunohistochemistry [86] in human granulosa cells by mRNA [33]; and in granulosa cells of sheep and cattle by mRNA [87,88]. However, others have failed to detect GLUT4 in mouse or rat granulosa cells by western blotting and mRNA hybridization [89,90]. Whether the cumulus cells or oocytes display insulin stimulated glucose uptake, and how insulin resistance may affect this process is unknown at this time.…”

Section: Glucosementioning

confidence: 99%

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The impact of obesity on egg quality

Purcell

Moley

2011

J Assist Reprod Genet

136

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Obesity in women is a concern in many countries. This causes numerous health issues; however, this review focuses on the impact of obesity on women's reproduction, and in particular the oocyte. Data from infertility clinics and experimental animal models that address the effects of obesity are presented. Bidirectional communication and metabolic support from the surrounding cumulus cells are critical for oocyte development, and the impact of obesity on these cells is also addressed. Both oocyte maturation and metabolism are impaired due to obesity, negatively impacting further development. In addition to reproductive hormones, obesity induced elevations in insulin, glucose, or free fatty acids, and changes in adipokines appear to impact the developmental competence of the oocyte. The data indicate that any one of these hormones or metabolites can impair oocyte developmental competence in vivo, and the combination of all of these factors and their interactions are the subject of ongoing investigations.

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Section: Insulinmentioning

confidence: 81%

Section: Glucosementioning

confidence: 99%

The impact of obesity on egg quality

Purcell

Moley

2011

J Assist Reprod Genet

136

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“…IGF-I stimulates nuclear maturation of cumulusenclosed oocytes (Gomez et al 1993, Yoshimura et al 1996, Pawshe et al 1998, and improves early embryonic development (Pawshe et al 1998). Moreover, IGF-I knockout mice have reduced glucose transporter expression, which is thought to be essential for oocyte maturation and successful ovulation (Zhou et al 2000). Since factors which accumulate in the oocyte may have a long-lasting effect on subsequent development, the IGF-I is likely to exert an effect on oocyte maturation in early follicle stages by binding to the cell surface receptors long before oocyte competence has been achieved.…”

Section: Discussionmentioning

confidence: 99%

Effects of IGF-I bioavailability on bovine preantral follicular development in vitro

Thomas¹,

Campbell²,

Armstrong³

et al. 2007

Reproduction

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The aim of this study was to determine the effect of regulation of IGF-I bioavailability on preantral follicle development in vitro. Bovine preantral follicles were cultured for 6 days in serum-free medium with increasing doses of Long R3 (LR3) IGF-I (an analog with low affinity for IGF-binding proteins (IGFBPs)), or human recombinant IGF-I (hrIGF-I). Follicle diameter and estradiol production were measured every second day. On day 6, ratios of oocyte/follicle diameter and oocyte morphology were assessed by histological examination, and IGFBP-2 and -3 were detected by immunocytochemistry and in situ hybridization respectively. Both types of IGF-I increased follicle diameter in a dose-dependent manner (P!0.05) and increased estradiol production over control levels (P!0.05). However, follicles treated with LR3 IGF-I and the highest concentration of hrIGF-I (1000 ng/ml) had smaller oocyte/follicle ratios, and increased oocyte degeneration, compared with controls or follicles treated with physiological concentrations of hrIGF-I (P!0.05). IGFBPs were detected in cultured preantral follicles, indicating a requirement for regulation of IGF bioavailability during the early stages of follicular development. Specifically, IGFBP-3 mRNA was found to be expressed in oocytes, and IGFBP-2 immunoreactivity was detected in oocytes and granulosa cells of cultured follicles. In summary, the regulation of IGF-I bioavailability by IGFBPs is necessary for the co-ordination of oocyte and follicle development in vitro.

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“…Release of significant amounts of IGF-I by cultured bovine and porcine follicles and granulosa cells has been demonstrated by Sirotkin et al [22]. Particularly high amounts of IGF-I are produced by cumulus cells [23]. The involvement of IGF-I in oocyte development has also been confirmed by the presence of its receptors in ovarian follicles and in immature oocytes [24][25][26].…”

mentioning

confidence: 91%

Apoptosis Inhibition by Insulin-Like Growth Factor (IGF)-I During In Vitro Maturation of Bovine Oocytes

Wasielak

Bogacki

2007

Journal of Reproduction and Development

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Abstract.Recently, significant progress has been achieved in improving the yield of good quality embryos in vitro. However, efforts are still required to recognize the factors and understand the mechanisms of oocyte maturation, which are essential for subsequent embryo development. The aims of the present study were to determine the frequency of apoptosis in oocytes recovered from slaughterhouse ovaries and to investigate whether insulin-like growth factor (IGF)-I action during oocyte maturation in vitro may withhold apoptosis and improve oocyte quality. Only oocytes of proper morphology with homogenous ooplasm and compact cumulus cells were selected for this study. All oocytes recovered from the slaughterhouse ovaries were divided into two groups. One group of oocytes, chosen for apoptosis detection, was examined immediately after recovery. The other group of oocytes was maturated in vitro. Oocytes were maturated with IGF-I supplementation (100 ng/ml). Oocytes without supplementation were used as a control. Apoptosis in oocytes was determined by positive results of TUNEL assay and active caspase labeling. The percentage of apoptotic oocytes detected by TUNEL fell to zero when the maturation medium was supplemented with IGF-I in comparison to the control matured oocytes (0 vs. 9.87%; P<0.05). However, active caspase labeling was only slightly decreased in the IGF-I matured oocytes compared with the control matured oocytes (1.13 vs. 2.08%; P<0.05). The results indicate that IGF-I may serve as an antiapoptotic factor during oocyte maturation. We suggest that IGF-I may inhibit apoptosis in oocytes at the stage of caspase activation and may prevent further advancement of oocyte apoptosis.

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Reduced GLUT1 expression in Igf1–/– null oocytes and follicles

Cited by 54 publications

References 12 publications

The impact of obesity on egg quality

The impact of obesity on egg quality

Effects of IGF-I bioavailability on bovine preantral follicular development in vitro

Apoptosis Inhibition by Insulin-Like Growth Factor (IGF)-I During In Vitro Maturation of Bovine Oocytes

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