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Abstract
Despite the fact that the fundamental principle underlying the most common method of culture media constitution is that of mimicking the natural environment of the preimplantation embryo, one major difference that remains between current embryo culture media and in vivo conditions is the absence of growth factors in vitro. Numerous growth factors are known to be present in the in vivo environment of human and nonhuman preimplantation embryos, often with peak concentrations corresponding to when fertilization and preimplantation embryo growth would occur. Although these growth factors are found in very small concentrations, they have a profound effect on tissue growth and differentiation through attachment to factor-specific receptors on cell surfaces. Receptors for many different growth factors have also been detected in human preimplantation embryos. Preimplantation embryos themselves express many growth factors. The growth factors and receptors are metabolically costly to produce, and thus their presence in the environment of the preimplantation embryo and in the embryo respectively strongly implies that embryos are designed to encounter and respond to the corresponding factors. Studies of embryo coculture also indirectly suggest that growth factors can improve in vitro development. Several animal and human studies attest to a probable beneficial effect of addition of growth factors to culture media. However, there is still ambiguity regarding the exact role of growth factors in embryonic development, the optimal dose of growth factors to be added to culture media, the combinatorial effect and endocrine of growth factors in embryonic development.
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Affiliation(s)
- Aparna Hegde
- Department of OB/GYN, Division of Reproductive Endocrinology and Infertility, Stanford University, Stanford, CA, USA
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The importance of growth factors for preimplantation embryo development and in-vitro culture. Curr Opin Obstet Gynecol 2008; 20:292-304. [PMID: 18460945 DOI: 10.1097/gco.0b013e3282fe743b] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE OF REVIEW The present paper reviews evidence that preimplantation embryos are naturally exposed and designed to respond to growth factors during preimplantation development. RECENT FINDINGS Recent studies have demonstrated that in-vivo human preimplantation embryos are exposed to a mixture of many different growth factors, expressed by the follicles, oviducts and endometrium. Receptors for many of these growth factors have also been shown to be expressed by preimplantation embryos, suggesting a functional role during preimplantation development. Studies of in-vitro fertilization in both animals and humans indicate that in-vitro culture of embryos in conventional media lacking growth factors can result in suboptimal growth and a variety of short-term and long-term developmental abnormalities. Studies of embryo coculture indirectly suggest that growth factors can improve in-vitro development. Many studies of defined growth factor supplements demonstrate that their inclusion in culture media can substantially improve preimplantation development and efficacy of in-vitro fertilization, and may reduce long-term developmental abnormalities as well. SUMMARY Embryos are naturally exposed to a complex mixture of growth factors that play an important role in preimplantation embryo development and that are likely to be of substantial benefit if added to in-vitro culture media.
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YAMANOUCHI K, IKEDA A, MATSUYAMA S, HASEGAWA T, SUGAWARA Y, NISHIHARA M, TOJO H, SAWASAKI T, MIYAZAWA K, TACHI C, TAKAHASHI M. Inhibin .ALPHA.-Subunit mRNA Is Expressed in the Corpus Luteum of the Pregnant Mare. J Reprod Dev 1997. [DOI: 10.1262/jrd.43.267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Keitaro YAMANOUCHI
- Laboratory of Applied Genetics, Institute of Animal Resource Sciences, Graduate School of Agriculture and Life Science, The University of Tokyo, Tokyo 113, Japan
| | - Akihiro IKEDA
- Department of Veterinary Physiology, Veterinary Medical Science, The University of Tokyo, Tokyo 113, Japan
| | - Shigemi MATSUYAMA
- Department of Veterinary Physiology, Veterinary Medical Science, The University of Tokyo, Tokyo 113, Japan
| | - Telhisa HASEGAWA
- Laboratory of Molecular and Cellular Biology, Equine Research Institute, Japan Racing Association, Tokyo 154, Japan
| | - Yukihiro SUGAWARA
- Laboratory of Livestock Biotechnology, Institute of Animal Resource Sciences, Graduate School of Agriculture and Life Science, The University of Tokyo, Tokyo 113, Japan
| | - Masugi NISHIHARA
- Department of Veterinary Physiology, Veterinary Medical Science, The University of Tokyo, Tokyo 113, Japan
| | - Hideaki TOJO
- Laboratory of Applied Genetics, Institute of Animal Resource Sciences, Graduate School of Agriculture and Life Science, The University of Tokyo, Tokyo 113, Japan
| | - Toru SAWASAKI
- Laboratory of Livestock Biotechnology, Institute of Animal Resource Sciences, Graduate School of Agriculture and Life Science, The University of Tokyo, Tokyo 113, Japan
| | - Kiyoshi MIYAZAWA
- Department of Veterinary Obstetric and Gynecology, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080, Japan
| | - Chikashi TACHI
- Laboratory of Applied Genetics, Institute of Animal Resource Sciences, Graduate School of Agriculture and Life Science, The University of Tokyo, Tokyo 113, Japan
| | - Michio TAKAHASHI
- Department of Veterinary Physiology, Veterinary Medical Science, The University of Tokyo, Tokyo 113, Japan
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Erämaa M, Heikinheimo K, Tuuri T, Hildén K, Ritvos O. Inhibin/activin subunit mRNA expression in human granulosa-luteal cells. Mol Cell Endocrinol 1993; 92:R15-20. [PMID: 8319822 DOI: 10.1016/0303-7207(93)90020-k] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We studied the expression of inhibin/activin subunit mRNAs in granulosa-luteal cells of preovulatory ovarian follicles obtained from women undergoing in vitro fertilization, and in corpus luteum tissue samples of early pregnancy. Northern analysis of granulosa-luteal cell and corpus luteum RNA with single-stranded cDNA or cRNA probes revealed an 1.6-kb mRNA for the alpha subunit and about 6.0-, 4.0-, 2.8-, and 1.7-kb transcripts for the beta A subunit. No clear hybridization signal for the beta B subunit could be detected. The relative expression levels of alpha and beta A subunit mRNAs were determined at 2-day intervals in granulosa-luteal cells cultured for 5 to 11 days. The levels of alpha subunit mRNAs declined steadily with increasing culture age, whereas those of beta A remained unchanged. Reverse transcription-polymerase chain reaction analysis with 35 amplification cycles confirmed the expression of alpha and beta A subunit mRNAs in cultured granulosa-luteal cells. The beta B transcripts were also weakly detectable by this sensitive assay. In situ hybridization of human early pregnancy corpus luteum revealed intense hybridization with the alpha cRNA probe and a weaker signal for the beta A subunit in the granulosa cell compartment. We conclude that: (1) the inhibin alpha and beta A subunits (and to a lesser extent beta B) are expressed in cultured human granulosa-luteal cells; (2) during extended culture periods the alpha/beta A mRNA expression ratio decreases; and that (3) the alpha and beta A subunit mRNA expression is observed in the granulosa cell compartment of early pregnancy corpora lutea.
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Affiliation(s)
- M Erämaa
- Department of Bacteriology and Immunology, University of Helsinki, Finland
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