Molecular Human Reproduction, Vol. 5, No. 1, 22-28,
January 1999
© 1999 European Society of Human Reproduction and Embryology
Expression of CD44 in human cumulus and mural granulosa cells of individual patients in in-vitro fertilization programmes
1 Department of Obstetrics and Gynecology, and 2 Department of Biochemistry, Yamagata University School of Medicine, Yamagata City 990-9585, Japan
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CD44 is a polymorphic and polyfunctional transmembrane glycoprotein widely expressed in many types of cells. Here, the expression of this protein on human membrana granulosa was studied by two techniques. Using confocal laser scanning microscopy (CLSM) with the mouse monoclonal antibody to human CD44 (clone G44–26), cells immunoreactive for CD44 were observed in both cumulus and mural granulosa cell masses. On the other hand, using monoclonal antibody to human CD44v9, goat polyclonal antibody to human CD44v3–10 and the clone G44–26, no immunoreactivity for CD44v9 and/or CD44v3–10 was observed in either cell group by flow cytometry. In the flow cytometric analysis of 32 patients, the incidence of CD44 expression in cumulus cells (62.6 ± 1.3%) was significantly higher than that in mural granulosa cells (38.5 ± 3.2%) (P < 0.0001). In the comparison of CD44 expression by flow cytometry according to the maturation of each cumulus–oocyte complex, the incidence of CD44 expression of cumulus cells was significantly higher in the mature group than in the immature group (P < 0.05). In a flow cytometric analysis, patients with endometriosis showed a significantly lower incidence of CD44 expression in cumulus cells compared to the infertility of unknown origin group (P < 0.05), and compared to both the male infertility group and the unknown origin group in mural granulosa cells (P < 0.01). These findings suggest that the standard form of CD44 is expressed in human membrana granulosa with polarity and may play an important role in oocyte maturation.
CD44/cumulus cells/hyaluronic acid/in-vitro fertilization/mural granulosa cells
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Introduction |
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Hyaluronic acid (HA) is an extracellular glycosaminoglycan found in most types of extracellular matrix in mammalian systems. HA has been found to cause cell aggregation in a number of different cell types and has been implicated in the stimulation of cell proliferation, cell migration and cell adhesion.
The presence of HA in the granulosa cell layer and the zona pellucida at the period of ovulation has been confirmed by many investigators. Antral follicles express HA in the cumulus oophorus and the membrana granulosa after the luteinizing hormone stimulation for ovulation induction (Salustri et al., 1992
). HA in cumulus or mural granulosa cells may be involved in cell–cell adhesion, the prevention of fragmentation or the segmentation of oocytes in vitro (Sato et al., 1987). We have recently demonstrated that HA prevents apoptosis in cumulus and mural granulosa cells (T.Kaneko et al., unpublished). Many of the effects of HA are thought to be mediated through cell surface receptors, such as CD44 (Underhill et al., 1987), CD54 (McCourt et al., 1994) and RHAMM (Turley et al., 1991; Hardwick et al., 1992).
CD44 is a ubiquitous multistructural and multifunctional cell surface adhesion molecule involved in cell–cell and cell–matrix interactions. The CD44 family belongs to a larger group of HA-binding proteins, termed the hyaladherins (Toole, 1990). Many of these proteins contain a sequence of amino acids homologous to the B loop of cartilage link protein, which appears to be important in the binding of HA. CD44 exists in a short standard form, CD44s (or CD44H), and in a number of large isoforms containing additional exon inserts; all forms are encoded by a single 19–20 exon gene (Jackson et al., 1992; Screaton et al., 1992) mapped, in the human, to the short arm of chromosome 11 (Goodfellow et al., 1982). All isoforms of CD44 are highly glycosylated by containing both N- and O-linked carbohydrate side-chains. Variations in the degree of glycosylation give rise to the multiple molecular mass forms of CD44.
CD44 and other variants are expressed on a wide variety of normal and abnormal cell types, including epithelial cells and haematopoietic cells such as lymphocytes (Fox et al., 1994; Mackay et al., 1994; Terpe et al., 1994). In reproductive biology, for example, CD44 has been detected in preimplanted human embryos at 1–8-cell stages (Campbell et al., 1995), and in human endometrium in the mid- to late secretory phase (Yaegashi et al., 1995).
Multiple functions for CD44 have been reported, particularly in the haematopoietic cells, e.g. as a homing receptor (Jalkanen et al., 1986), in the transmission of growth signals (Bourguignon et al., 1993; Tsukita et al., 1994; Entwistle et al., 1996), participation in the uptake and intracellular degradation of HA (Culty et al., 1992), cell traffic (Naor et al., 1997), cell aggregation (Belitsos et al., 1990), the induction of haematopoiesis (Miyake et al., 1990) and the induction or inhibition of cell apoptosis (Ayroldi et al., 1995; Henke et al., 1996). The physiological roles of CD44 in epithelium, however, are not well documented as yet. Little information has been obtained regarding the expression and function of CD44 in granulosa cells during follicular development, ovulation and luteinization.
In this study, two techniques, confocal laser scanning microscopy (CLSM) and flow cytometry, were used to investigate: (i) whether CD44 is present on the surface of a human cumulus and mural granulosa cells; (ii) which type of isoforms are expressed in these granulosa cells; (iii) whether there is a difference in the expression of this molecule between these two kinds of granulosa cells; (iv) whether there is a relationship between oocyte maturation and the expression of CD44 in granulosa cells; and (v) whether endometriosis is accompanied by reduced expression of CD44 in granulosa cells.
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Patients and follicle stimulation protocol
Granulosa cells were obtained from patients involved in in-vitro fertilization (IVF) programmes at Yamagata University Hospital, Yamagata, Japan. The patients gave informed consent to this study. Each patient was administered 600 µg of buserelin acetate/day (Suprecur nasal; Hoescht Marion Roussel, Tokyo, Japan) for pituitary desensitization beginning in the mid-luteal phase of the preceding menstrual cycle. Human menopausal gonadotrophin (HMG, Humegon 150–300 IU/day; Sankyo, Tokyo, Japan) and/or pure follicle stimulating hormone (FSH, Fertinom P; Serono, Tokyo, Japan) were administered starting on day 3 of the menstrual cycle. Human chorionic gonadotrophin (HCG, 10 000 IU; Mochida, Tokyo, Japan) was administered when the leading follicle enlarged to a mean diameter of
15.5 mm. Follicles were aspirated by transvaginal ultrasound retrieval (6.5 MHz; Mochida) at 35 h after the administration of HCG.
Cell preparation of cumulus and mural granulosa cells
All follicles with a mean diameter of 11 mm were aspirated using a 20 ml syringe. The aspirates were placed in a dish (Falcon 3001), and the cumulus oocyte complexes were washed twice with culture medium and then transferred into another culture dish. Cumulus granulosa cells were separated manually from an oocyte with a 26 gauge needle. Mural granulosa cells were separated from the follicular fluid by centrifugation for 5 min at 480 g using a 80% Percoll gradient medium. The granulosa cells were then picked out manually and washed and precipitated three times in phosphate-buffered saline (PBS). During these procedures, almost all contaminated blood cells were removed. Cumulus cells and mural granulosa cells were dispersed by 0.1% hyaluronidase with gentle pipetting. After these granulosa cells were washed and centrifuged three times with PBS, the cell pellet was resuspended in PBS and used for further examination immediately.
Immunofluorescence
The prepared cells were placed on a slide glass, dried thoroughly, and fixed with 100% ethanol for 10 min. Mouse monoclonal antibody to human CD44 (clone G44–26, Pharmingen, San Diego, CA, USA), prepared as a 1:100 dilution in PBS, was added to each sample, and then the samples were incubated at room temperature for 1 h. G44–26 detects not only the standard type but also all other isoforms because this antibody recognizes the domain common to all types of CD44. On the other hand, CD44v9 and CD44v3–10 detect only the corresponding variant isoforms. The samples were washed to remove excess first antibody and then incubated with fluorescein isothiocyanate (FITC)-conjugated anti-mouse immunoglobulin (IgG) (1:100 in PBS; Calbiochem–Novabiochem International, San Diego, CA, USA) for 1 h at room temperature in a dark box. The samples incubated with second antibody alone were used as negative controls. The cells were then washed three times with PBS and stained by propidium iodide solution (2 µg/ml, Sigma-Aldrich Japan, Tokyo; RNase A, 1 mg/ml, Sigma-Aldrich Japan) for 10 min, and washed three times with PBS, and then finally mounted with 5% wt/vol of 1,4-diazabiccyclo2,2,2-octane, (Dabco; Sigma Chemical Co, St Louis, MO, USA) in 90% glycerol:10% 0.2 M Na2HPO3. The expression of CD44 was observed immediately after staining under a CLSM (TCS4D, Leica, Heidelberg, Germany).
Fluorescence-activated cell surface (FACS) analysis
The cells prepared by the procedures above were adjusted to 5 x 106 cells/ml with PBS. The first antibody (20 µl) was added to 50 µl of prepared cell suspension in a round-bottomed tube (Falcon 2003) and incubated at 4°C for 30 min in the dark. Then the second antibody reactive with each first antibody was added and incubated at 4°C for 30 min. After the samples were washed with PBS, cells were fixed with 50 µl of 1% paraformaldehyde.
The following antibodies were used for this analysis: (i) the first antibodies, FITC-conjugated mouse anti-human CD44 monoclonal antibody (clone G44–26, Pharmingen), goat anti-human CD44v9 monoclonal antibody (Seikagaku, Tokyo, Japan); isotype-matched control antibody (FITC-conjugated mouse IgG2b, k; Pharmingen); the second antibodies; FITC-conjugated rabbit anti-goat immunoglobulins (DAKO Glostrup, Denmark), FITC-conjugated goat anti-mouse IgG (Calbiochem, La Jolla, CA, USA). The isoforms which each antibody detects are given above.
Flow cytometric analysis was performed with a FACS Calibur (Becton Dickinson, Mountain View, CA, USA). The data obtained are presented as single-parameter frequency distribution histograms (x = intensity of fluorescence; y = number of cells) for the cell population, which was determined by placing an electronic gate in the dot plot. Clumps of granulosa cells and other residual blood cells were electronically excluded from the analyses in each procedure. The rate of CD44-positive cells was calculated by comparing the number of cells in the negative control with that of the cells with more intense fluorescein in the specimens on the histogram.
Measurement of serum hormone concentrations
Quantification of serum hormone concentration was carried out using commercially avaialable immunoassay: oestradiol, progesterone, FSH, luteinizing hormone (LH), prolactin and HCG by chemiluminescent enzyme immunoassay system (Immulyse; Diagnostic Products Corporation, Los Angeles, CA, USA).
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Expression of CD44 in the cumulus and mural granulosa cells
Confocal laser scanning-microscopic examination clearly revealed immunoreactivity to CD44 (G44–26 antibody) in cumulus and mural granulosa cell masses. The majority of the cumulus granulosa cells showed immunoreactivity for CD44. Immunostaining was present in the cytoplasm but especially on the plasma membrane (Figure 1A
). The positive cells were distributed in a scattered and irregular fashion. In the mural granulosa cells, the staining pattern in the positive cells was similar, but the rate of stained cells was lower than that of the cumulus cells (Figure 1B). No specific immunoreactivity was observed in the control cells that had been incubated without the G44-26 antibody (Figure 1C,D).
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In the flow cytometric analyses, 93.5% of the cumulus cells (Figure 2A
) and 34.5% of the mural granulosa cells (Figure 2B) were judged to be positive with anti-CD44 antibody (clone G44–26). In contrast, no immunoreactivity was detected with anti-CD44v9 antibody in cumulus cells (Figure 2C) and mural granulosa cells (Figure 2D), or with anti-CD44v3–10 antibody in cumulus cells (Figure 2E) and mural granulosa cells (Figure 2F). These results clearly indicate that CD44 is found in the human membrana granulosa.
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Higher expression of CD44 in cumulus cells than that in mural granulosa cells
Samples of cumulus cells and mural granulosa cells from 32 patients were analysed by flow cytometry. The incidence of CD44 expression in the cumulus cells (62.6 ± 1.3%) was significantly higher than that in the mural granulosa cells (38.5 ± 3.2%) (P < 0.0001) (Figure 3
).
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Increase of CD44-positive cells in matured cumulus–oocyte complexes (COC)
A total of 35 cumulus masses from seven patients were used to analyse the relationship between the incidence of CD44 expression in cumulus cells and the maturity of COC by flow cytometry. All cumulus masses were classified as immature or mature (Marrs et al., 1984
). The incidence of CD44 expression was measured after unifying individual cumulus masses of the same patients in the same maturity groups, because the cell counts per one cumulus mass were not sufficient for the flow cytometric analysis. The incidence of CD44 expression in the mature cumulus mass group was significantly higher than that in the immature group (P < 0.05) (Figure 4).
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Decrease of CD44 positive cells in patients with endometriosis
The incidence of CD44 expression of each granulosa cell group was compared in the same group of 32 patients classified into the following infertility factor groups: tubal infertility (n = 9), endometriosis (n = 8), male infertility (n = 8), and infertility of unknown origin (n = 7) (Table I
). Endometriosis was staged according to the revised American Fertility Society classification (AFS, 1985). All patients in the endometriosis group were classified as AFS III or IV. The patients with endometriosis showed a significantly lower incidence of CD44 expression in cumulus granulosa cells compared with the unknown origin group (P < 0.05) (Table II). Regarding the mural granulosa cells, the patients with endometriosis showed a significantly lower CD44 expression compared with both the male infertility group and the unknown origin group (P < 0.01) (Table II).
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Discussion |
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It has been reported that cultured human cumulus granulosa cells express CD44 (Campbell et al., 1995
). Using an immunohistochemical staining method, another investigator observed the expression of CD44s on follicular epithelium of the ovary (Terpe et al., 1994), but others reported no expression of CD44 in ovarian tissue (Fox et al., 1994) nor in ovarian epithelium (Mackay et al., 1994). These discrepancies can be attributed to technical differences in methodology, variations of staining sensitivity, and/or the difference in antibodies that recognize different epitopes. To our knowledge, no reports have been published on the expression of CD44 in membrana granulosa of mammals, other than in humans. In our study, the plasma membrane alone was stained in some granulosa cells; however, in the majority of granulosa cells, the cytoplasm was also stained. This difference of immunoreactivity may be attributable to the different degree of permeation of antibodies through the plasma membrane and cytoplasm.
A complete elucidation of the cells expressing standard CD44 or its variants at distinct states of differentiation or activation would contribute to the evaluation of CD44 function. It is difficult to ignore the finding that epithelial regions which are rich in proliferating cells (such as the basal cells of stratified squamous epithelium and glandular epithelium) express high levels of CD44 variants, especially isoforms containing the v6 exon. Similarly, activated leukocytes and epithelial cells having generative activities within the embryo also showed a marked expression of CD44 variants. Many investigators have reported that malignant cells, which share many properties with normal cells of generative tissues, bear similar CD44 isoforms (Horst et al., 1990; Gunthert et al., 1991; Arch et al., 1992; Kuppner et al., 1992; Naor et al., 1997). Granulosa cells are known to be typical proliferating epithelial cells, because of the coating of surfaces and lining of cavities with continuous sheets of these cells connecting via gap junctions and underlying the basement membrane; however, the present results indicated that the CD44 expressed in granulosa cells was mainly the standard form (CD44s), not other isoforms. These findings suggest that the granulosa cells are differentiated from epithelial cells and have different functions. In the light of findings that only CD44s can bind to HA, and that CD44E cannot bind to HA (Stamenkovic et al., 1991), the signal pathway of HA–CD44 may play an important role in the function of the granulosa cells.
This study was performed by separating the cumulus cells from the mural granulosa cells, because cellular heterogeneity within the follicular epithelium at various stages of follicular development was reported with respect to cell size (Rao et al., 1991; Kerketze et al., 1995), cell function (Hartshorne, 1990) and cell survival (Nakahara et al., 1997. These variables, particular in cumulus cells, may be of developmental significance for the enclosed oocyte. Recently, two studies (Gloria and Jonathon, 1997; Michael et al., 1997) on cumulus–oocyte interactions have been reported. This is the first study which demonstrated a difference in CD44 expression between cumulus cells and mural granulosa cells. Since the cumulus granulosa cells which surround an oocyte closely, showed stronger CD44 expression than the mural granulosa cells, CD44 may have some important effects on the oocyte.
It is known that the LH surge in mid-cycle or a well-timed injection of HCG, oocyte maturation is initiated in the fully grown follicles. Some investigators reported that various factors in follicles such as gap junctions (Racowsky et al., 1989), cAMP (Dekel et al., 1980), calcium (Goren et al., 1990), and growth factors and steroids (Edwards, 1990) are associated with oocyte maturation. Changes in these factors in the follicle at the time of preovulation may regulate oocyte maturation. No studies have been reported on the effects of CD44 on the maturation of an oocyte. Since in the present study the granulosa cells of the mature COC had a CD44 expression much higher than that of the immature COC, and since the mature COC contains more HA than the immature COC, the signal pathway of HA–CD44 might have an important influence on oocyte maturation.
Endometriosis is one of the most enigmatic of gynaecological diseases. A perplexing problem is the link between endometriosis and infertility. The mechanism of infertility associated with endometriosis without obvious pelvic adhesive disease is poorly understood, and the best treatment is therefore unknown (Gleicher, 1992). Many possible mechanisms of this disorder have been suggested, including altered folliculogenesis (Tummon et al., 1988), ovulatory dysfunction (Dmowski et al., 1986), reduced preovulatory steroidogenesis of granulosa cells (Harlow et al., 1996), sperm phagocytosis (Soldati et al., 1989), impaired fertilization (Mahadevan et al., 1983; Wardle et al., 1985), embryo toxicity against early embryonic development (Damewood et al., 1990; Simón et al., 1992), defective implantation (Matson and Yovich, 1986), and alterations within the oocyte, which in turn result in embryos with a decreased ability to implant (Simón et al., 1994). In this study, we have demonstrated a relationship between oocyte maturation and the CD44 expression in the granulosa cells, and we have found that the CD44 expression of the granulosa cells in the endometriosis patients was significantly depressed. This depression of CD44 in the granulosa cells surrounding oocytes probably influences the quality of the oocytes. This depression may be one of the reasons why endometriosis patients have relatively poor fecundity.
In conclusion, the results of this study indicate that CD44 is expressed in luteinizing human membrana granulosa and may play important roles in oocyte maturation. Additional studies are required to define in detail the expression and roles of the CD44 family in the granulosa cells during folliculogenesis and the menstrual cycle.
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Acknowledgments |
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We gratefully acknowledge the patients who donated materials, Dr Hiroshi Watanabe and Dr Kaoru Goto for their helpful suggestions, and Dr Kanji Hatano for his technical assistance.
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3 To whom correspondence should be addressed
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References |
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American Fertility Society (1985) Revised American Fertility Society classification of endometriosis. Fertil. Steril., 43, 351–352.[Medline]
Arch, R., Wirth, K., Hofmann, M. et al. (1992) Participation in normal immune responses of a metastasis-inducing splice variant of CD44. Science, 257, 682–685.
Ayroldi, E., Cannarile, L., Migliorati, G. et al. (1995) CD44 (Pgy-1) inhibits CD3 and dexamethason-induced apoptosis. Blood, 86, 2672–2678.
Belitsos, P.C., Hildreth, J.E.K. and August, J.T. (1990) Homotypic cell aggregation induced by anti-CD44 (Pgp-1) monoclonal antibodies and related to CD44 (Pgp-1) expression. J. Immunol., 144, 1661–1670.[Abstract]
Bourguignon, L.Y.W., Lokeshwar, V.B., Chen. X. et al. (1993) Hyaluronic acid-induced lymphocyte signal transduction and HA receptor (GP85/CD44)-cytoskeleton interaction. J. Immunol., 151, 6634–6644.[Abstract]
Campbell, S., Swann, H.R., Aplin, J.D. et al. (1995) CD44 is expressed throughout pre-implantation human embryo development. Hum. Reprod., 10, 425–430.
Culty, M., Nguyen, H.A. and Underhill, C.B. (1992) The hyaluronan receptor (CD44) participates in the uptake and degradation of hyaluronan. J.Cell. Biol., 116, 1055–1062.
Damewood, M.D., Hesla, J.S., Schlaff, W.D. et al. (1990) Effect of serum from patients with minimal to mild endometriosis on mouse embryo development in vitro. Fertil. Steril., 54, 917–920.[ISI][Medline]
Dekel, N. and Beers, W.H. (1980) Development of the rat oocyte in vitro: inhibition and induction of maturation in the presence or absence of the cumulus oophorus. Dev. Biol., 75, 247–254.[ISI][Medline]
Dmowski, W.P., Radwanska, E., Binor, Z. et al. (1986) Mild endometriosis and ovulatory dysfunction: effect of danazol treatment on success of ovulation induction. Fertil. Steril., 46, 784–789.[ISI][Medline]
Edwards, R.G. (ed.) (1990) Establishing a Successful Human Pregnancy. Raven Press, New York, USA.
Entwistle, J., Hall, C.L. and Turley, E.A. (1996) HA receptors:regulators of signaling to the cytoskeleton. J. Cell. Biochem., 61, 569–577.[ISI][Medline]
Fox, S.B., Fawcett, J., Jackson, D.G. et al. (1994) Normal human tissues, in addition to some tumors, express multiple different CD44 isoforms. Cancer Res., 54, 4539–4546.
Gleicher, N. (1992) Endometriosis: a new approach is needed. Hum. Reprod., 7, 821–824.
Gloria, I.P. and Jonathan, L.T. (1997) Cumulus cells are required for the increased apoptotic potential in oocytes of aged mice. Hum. Reprod., 12, 2781–2783.
Goodfellow, P.N., Banting, G. and Wiles, M.V. (1982) The gene, MIC4, which controls expression of the antigen defined by monoclonal antibody F10. 44.2, is on human chromosome 11. Eur. J. Immunol., 12, 659–663.[ISI][Medline]
Goren, S., Oron, Y. and Dekel, N. (1990) Rat oocyte maturation: role of calcium in hormone action. Mol. Cell. Endocrinol., 72, 131–138.[ISI][Medline]
Gunthert, U., Hofmann, M., Rudy, W. et al. (1991) A new variant of glycoprotein CD44 confers metastatic potential to rat carcinoma cells. Cell, 65, 13–24.[ISI][Medline]
Hardwick, C., Hoare, K., Owens, R. et al. (1992) Molecular cloning of a novel hyaluronan receptor that mediates tumor cell motility. J. Cell. Biol., 117, 1343–1350.
Harlow, C.R., Cahill, D.J., Maile, L.A. et al. (1996) Reduced preovulatory granulosa cell steroidogenesis in women with endometriosis. J. Clin. Endocrinol. Metab., 81, 426–429.[Abstract]
Hartshorne, G.M. (1990) Subpopulations of granulosa cells within the human ovarian follicle. J. Reprod. Fertil., 89, 773–782.[Abstract]
Henke, C., Bitterman, P., Roongta, U. et al. (1996) Induction of fibroblast apoptosis by anti-CD44 antibody. Am. J. Pathol., 149, 1639–1650.[Abstract]
Horst, E., Meijer, C.J.L.M., Radaszkiewicz, T. et al. (1990) Adhesion molecules in the prognosis of diffuse large-cell lymphoma: expression of a lymphocyte homing receptor (CD44), LFA-1 (CD11a/18), and ICAM-1 (CD54). Leukemia, 4, 595–599.[ISI][Medline]
Jackson, D.G., Buckley, J. and Bell, J.I. (1992) Multiple variants of the human lymphocyte homing receptor CD44 generated by insertions at a single site in the extracellular domain. J. Biol. Chem., 267, 4732–4739.
Jalkanen, S.T., Bargatze, R.F., Herron, L.R. et al. (1986) A lymphoid cell surface glycoprotein involved in endothelial cell recognition and lymphocyte homing in man. Eur. J. Immunol., 16, 1195–1202.[ISI][Medline]
Kerketze, K., Blaschuk, O.W. and Farookhi, R. (1995) Cellular heterogeneity in the membrana granulosa of developing rat follicles:assessment by flow cytometry and lectin binding. Endocrinology, 137, 3089–3100.[Abstract]
Kuppner, M.C., Van Meir, E., Gauthier, Th. et al. (1992) Differential expression of the CD44 molecule in human brain tumours. Int. J. Cancer, 50, 572–577.[ISI][Medline]
Mackay, C.R., Terpe, H.J., Stauder, R. et al. (1994) Expression and modulation of CD44 variant isoforms in humans. J. Cell. Biol., 124, 71–82.
Mahadevan, M.M., Trounson, A.O. and Leeton, J.F. (1983) The relationship of tubal blockage, infertility of unknown cause, suspected male infertility, and endometriosis to success of in vitro fertilization and embryo transfer. Fertil. Steril., 40, 755–762.[ISI][Medline]
Marrs, R.P., Saito, H., Yee, B. et al. (1984) Effect of variation of in vitro culture techniques upon oocyte fertilization and embryo development in human in vitro fertilization procedures. Fertil. Steril., 41, 519–523.[ISI][Medline]
Matson, P.L. and Yovich, J.L. (1986) The treatment of infertility associated with endometriosis by in vitro fertilization. Fertil. Steril., 46, 432–434.[ISI][Medline]
McCourt, P.A.G, Ek, B., Forsberg, N. et al. (1994) Intercellular adhesion molecule-1 is a cell surface receptor for hyaluronan. J. Biol. Chem., 269, 30081–30084.
Michael, A., Jonathan, V.B., Andrew, C. et al. (1997) A novel mechanism of vascular endothelial growth factor, leptin and transforming growth factor-ß2 sequestration in a subpopulation of human ovarian follicle cells. Hum. Reprod., 12, 2226–2234.
Miyake, K., Medina, K., Hayashi, S. et al. (1990) Monoclonal antibodies to Pgp-1/CD44 block lympho-hemopoiesis in long-term bone marrow cultures. J. Exp. Med., 171, 477–488.
Nakahara, K., Saito, H., Saito, T. et al. (1997) Incidence of apoptotic bodies in membrana granulosa of the patients participating in an in vitro fertilization program. Fertil. Steril., 67, 302–308.[ISI][Medline]
Naor, D., Sionov, R.V. and Shalom, D.I. (1997) CD44: structure, function, and association with the malignant process. Adv. Cancer Res., 241–319.
Racowsky, C. and Baldwin, K.V. (1989) In vitro and in vitro studies reveal that hamster oocyte meiotic arrest is maintained only transiently by follicular fluid, but persistently by membrana/cumulus granulosa cell contact. Dev. Biol., 134, 297–306.[ISI][Medline]
Rao, I.M., Milis, T.M., Anderson, E. et al. (1991) Heterogeneity in granulosa cells of developing rat follicles. Anat. Rec., 229, 177–185.[Medline]
Salustri, A., Yanagishita, M., Underhill, C.B. et al. (1992) Localization and synthesis of hyaluronic acid in the cumulus cells and mural granulosa cells of the preovulatory follicle. Dev. Biol., 151, 541–551.[ISI][Medline]
Sato, E., Ishibashi, T. and Koide, S.S. (1987) Prevention of spontaneous degeneration of mouse oocytes in culture by ovarian gycosaminoglycans. Biol. Reprod., 37, 371–376.[Abstract]
Screaton, G.R., Bell., M.V. and Jackson, D.G. (1992) Genomic structure of DNA encoding the lymphocyte homing receptor CD44 reveals at least 12 alternatively spriced exons. Proc. Natl. Acad. Sci. USA, 89, 12160–12164.
Simón, C., Gomez, E., Mir, A. et al. (1992) Glucocorticoid treatment decreases sera embryotoxicity in endometriosis patients. Fertil. Steril., 58, 284–289.[ISI][Medline]
Simón, C., Gutierrez, A., Vidal, A. et al. (1994) Outcome of patients with endometriosis in assisted reproduction:results from in-vitro fertilization and oocyte donation. Hum. Reprod., 9, 725–729.
Soldati, G., Piffaretti-Yanez, A., Campana, A. et al. (1989) Effect of peritoneal fluid on sperm motility and velocity distribution using objective measurements. Fertil. Steril., 52, 113–119.[ISI][Medline]
Stamenkovic, I., Aruffo, A., Amiot, M. et al. (1991) The hematopoietic and epithelial forms of CD44 are distinct polypeptides with different adhesion potentials for hyaluronate-bearing cells. EMBO J., 10, 343–347.[ISI][Medline]
Terpe, H.J., Stark, H., Prehm, P. et al. (1994) CD44 variant isoforms are preferentially expressed in basal epithelia of non-malignant human fetal and adult tissues. Histochemistry, 101, 79–89.[ISI][Medline]
Toole, B.P. (1990) Hyaluronan and its binding proteins, the hyaladherins. Curr. Opin. Cell. Biol., 2, 839–844.[Medline]
Tsukita, S., Oishi, K., Sato, N. et al. (1994) ERM family members as molecular linkers between the cell surface glycoprotein CD44 and actin-based cytoskeletons. J. Cell. Biol., 126, 391–401.
Tummon, I.S., Maclin, V.M., Radwanska, E. et al. (1988) Occult ovulatory dysfunction in women with minimal endometriosis or unexplained infertility. Fertil. Steril., 50, 716–720.[ISI][Medline]
Turley, E.A., Austen, L., Vandeligt, K. et al. (1991) Hyaluronan and a cell-associated hyaluronan binding protein regulate the locomotion of ras-transformed cells. J. Cell. Biol., 112, 1041–1047.
Underhill, C.B., Green, S.J., Comoglio, P.M. et al. (1987) The hyaluronate receptor is identical to a glycoprotein of Mr 85000(gp85) as shown by a monoclonal antibody that interferes with binding activity. J. Biol. Chem., 262, 13142–13146.
Wardle, P.G., Mitchell, J.D., McLaughlin, E.A. et al. (1985) Endometriosis and ovulatory disorder:reduced fertilization in vitro compared with tubal and unexplained infertility. Lancet, ii, 236–239.
Yaegashi, N., Fujita, N., Yajima, A. et al. (1995) Menstrual cycle dependent expression of CD44 in normal human endometrium. Hum. Pathol., 26, 862–865.[ISI][Medline]
Submitted on April 7, 1998; accepted on October 1, 1998.
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  M. Assidi, I. Dufort, A. Ali, M. Hamel, O. Algriany, S. Dielemann, and M.-A. Sirard Identification of Potential Markers of Oocyte Competence Expressed in Bovine Cumulus Cells Matured with Follicle-Stimulating Hormone and/or Phorbol Myristate Acetate In Vitro Biol Reprod, August 1, 2008; 79(2): 209 - 222. [Abstract] [Full Text] [PDF]
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 M. Shimada, Y. Yanai, T. Okazaki, N. Noma, I. Kawashima, T. Mori, and J. S. Richards Hyaluronan fragments generated by sperm-secreted hyaluronidase stimulate cytokine/chemokine production via the TLR2 and TLR4 pathway in cumulus cells of ovulated COCs, which may enhance fertilization Development, June 1, 2008; 135(11): 2001 - 2011. [Abstract] [Full Text] [PDF]
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 D. L. Russell and R. L. Robker Molecular mechanisms of ovulation: co-ordination through the cumulus complex Hum. Reprod. Update, May 1, 2007; 13(3): 289 - 312. [Abstract] [Full Text] [PDF]
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M. Schoenfelder and R. Einspanier Expression of Hyaluronan Synthases and Corresponding Hyaluronan Receptors Is Differentially Regulated During Oocyte Maturation in Cattle Biol Reprod, July 1, 2003; 69(1): 269 - 277. [Abstract] [Full Text] [PDF]
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 A. E. Stock, N. Bouchard, K. Brown, A. P. Spicer, C. B. Underhill, M. Dore, and J. Sirois Induction of Hyaluronan Synthase 2 by Human Chorionic Gonadotropin in Mural Granulosa Cells of Equine Preovulatory Follicles Endocrinology, November 1, 2002; 143(11): 4375 - 4384. [Abstract] [Full Text] [PDF]
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 S. Varani, J. A. Elvin, C. Yan, J. DeMayo, F. J. DeMayo, H. F. Horton, M. C. Byrne, and M. M. Matzuk Knockout of Pentraxin 3, a Downstream Target of Growth Differentiation Factor-9, Causes Female Subfertility Mol. Endocrinol., June 1, 2002; 16(6): 1154 - 1167. [Abstract] [Full Text] [PDF]
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N. Kimura, Y. Konno, K. Miyoshi, H. Matsumoto, and E. Sato Expression of Hyaluronan Synthases and CD44 Messenger RNAs in Porcine Cumulus-Oocyte Complexes During In Vitro Maturation Biol Reprod, March 1, 2002; 66(3): 707 - 717. [Abstract] [Full Text] [PDF]
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