Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cumulus Cells”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1984

Purification of boar acrosomal arylsulfatase A and possible role in the penetration of cumulus cells.

Arylsulfatase A was extracted and purified from boar epididymal sperm acrosomes. Acrosomes were extracted by sonication in 50 mM Tris-maleate buffer containing 50 mM MgCl2, pH 6.1, followed by treatment with 50 mM Tris-maleate plus 0.2% Brij-35, pH 6.1. Purification of arylsulfatase A was performed with a three-step procedure consisting of centrifugation (85,000 X g), affinity chromatography with p-aminobenzamidine-Sepharose followed by chromatography on diethyaminoethyl (DEAE) Sephadex. The specific activity of the purified enzyme was 54 mumol/h per mg protein. The purified arylsulfatase did not contain any detectable acrosin or hyaluronidase activities. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis revealed a major band with an estimated molecular weight of 65,000 daltons. Properties of arylsulfatase A, determined by hydrolysis of p-nitrocatechol sulfate, indicated that the enzyme was inhibited 46% by 3.1 microM Ag+ and had a pH optimum of 4.2. Boar acrosomal arylsulfatase A dispersed the cumulus cells of ovulated hamster and rabbit eggs as well as those of follicular pig eggs. No effect of the enzyme on the zona pellucida or the oolemma was observed.

Acrosome↗
PubMed1997

In vitro fertilization in mice: Strain differences in response to superovulation protocols and effect of cumulus cell removal.

Strain differences have proven to be crucial components in mouse in vitro fertilization (IVF) and superovulatory protocols. To maximize the yield of IVF-derived mouse eggs, a series of experiments was conducted using different injection timing intervals for administration of pregnant mare serum gonadotropin (PMSG) and hCG to induce follicular development and ovulation. Strains were chosen that were representative of those commonly used in genetic engineering experimentation. These strains included ICR outbred, C57BL/6 inbred, and B6SJLF1 hybrid (C57BL/6J x SJL/J F1) mice. Females were superovulated using 4 PMSG/hCG/IVF timing regimens (group), with sperm obtained from males of the same strain. Group designations were based on the following PMSG/hCG and hCG/oocyte collection intervals, respectively: Group 1, 55 and 21.5 h; Group 2, 60 and 14.5 h; Group 3, 55 and 14.5 h; Group 4, 48 and 14.5 h. After overnight culture of ova, fertilization rates (development to the 2-cell stage) were assessed. A logistic regression was performed using indicator variables for both strain and group. There was a significant strain influence on ova fertilization rate, based on the coefficients of mouse strain (ICR, beta = -1.1067, P = 8E-17 and C57BL/6, beta = -0.5172, P = 8E-06). Additionally, group affected the proportion of fertilized ova obtained (coefficient of Group 1, beta = -1.3152, P = 0.00 and Group 3, beta = 0.9531, P = 3E-12). From the coefficients for the interaction terms, the effect of groups varies across mouse strain. Therefore, the treatment that produces the highest fertilization rate is related to and contingent upon the strain of mouse. In the second study, the Group 3 protocol was used to evaluate fertilization differences between cumulus-intact and cumulus-free oocytes. Again, there was a significant strain influence on ova fertilization rate based on the coefficients of mouse strain (ICR, beta = -2.6639, P = 0.00; C57BL/6, beta = -2.5114, P = 0.00). However, there was no difference between Cumulus and No Cumulus groups (cumulus coefficient, beta = 0.1640, P = 0.59872), indicating that there was no affect of cumulus presence on fertilization rate. In summary, responses to standardized mouse IVF protocols vary significantly. The efficiency of IVF procedures can be optimized between and within specific mouse strains by the timing of superovulatory regimens. However, absence of cumulus cells during the IVF procedure does not adversely affect fertilization rate.

Journal Article↗
PubMedDate not supplied

Exposure of pig oocytes to PCBs during in vitro maturation: effects on developmental competence, cytoplasmic remodelling and communications with cumulus cells.

Polychlorinated biphenyls (PCBs) are one of the most persistent and widespread groups of endocrine disrupting compounds in the ecosystem. These substances are present in sewage sludge that is spread in increasing amounts on arable land and pasture as fertilizer, and are ingested by farm animals with food and drinking water. This study investigated the effect of different PCB concentrations on pig oocyte in vitro maturation and developmental competence as well as examined the possible mechanisms involved. A concentration ranging from 0 to 1 mg/mL of Aroclor 1254 (A1254), a pool of more than 60 PCB congeners, was added to the maturation medium, as its composition is considered environmentally relevant. A1254 had no effect on maturation of pig oocytes and on the number of oocytes that cleaved following parthenogenetic activation at any of the doses tested. By contrast, a significant decrease in the number of zygotes that developed to blastocyst stage became evident at a concentration of 10 ng/mL. The number of blastocysts obtained decreased significantly, and in a dose response manner with higher concentrations. Exposure to PCBs altered mitochondria relocation during maturation and this was associated with the lack of a cytoplasmic microtubule network. No effect on mitochondria activity was observed. A1254 exposure also perturbed gap-junction mediated communications between oocytes and cumulus cells. In conclusion, PCB exposure of pig oocytes during in vitro maturation significantly decreased oocyte developmental competence, altered both their cytoplasmic remodelling and the communication with the somatic compartment. These data indicated that accumulation of PCBs in the pig organism may have a detrimental effect on the reproductive efficiency in this species.

Animals↗
PubMed1998

In vitro stimulation of cumulus-cell expansion by human cord serum in mouse oocyte-cumulus complexes.

PURPOSE: The aim of this study was to test whether human cord serum (HCS) containing gonadotropins has an effect on the expansion of oocyte-cumulus complexes (OCCs). METHODS: The concentration of follicle stimulating hormone (FSH) and luteinizing hormone (LH) was measured in HCS by radioimmunoassay (RIA). After short-term culture (4 hr) with or without OCCs, medium containing 0.4% bovine serum albumin (BSA) as control or 10% HCS was collected and analyzed for its concentration of estradiol, progesterone, and testosterone. RESULTS: The FSH concentration was at the basal level, but the LH level was as high as 142.4 mIU/ml in both natured and denatured serum. Undetectable levels of steroids were observed in control media with or without OCCs. In contrast, a moderate amount of steroid hormones was detected in culture medium containing HCS. OCCs secreted a minute amount of steroid hormones in response to HCS. Similar patterns of cumulus expansion were observable by treatment with HCS, human chorionic gonadotropin (hCG), or HCS plus hCG after 4, 8, or 22 hr of culture. However, no cumulus expansion was observed in controls. CONCLUSION: These results suggest that LH in HCS induces cumulus expansion but does not affect the secretion of steroid hormones by OCCs during culture.

Animals↗
PubMed1994

Increasing progesterone secretion and 3 beta-hydroxysteroid dehydrogenase activity of human cumulus cells and granulosa-lutein cells concurrent with successful fertilization of the corresponding oocyte.

In many studies it has been documented that the induction of multiple follicular growth in humans results in an asynchrony between the degree of cumulus mucification, oocyte meiotic maturation, fertilizability, and follicular cell progesterone (P4) secretion. The present study was carried out on oocytes enclosed in fully mucified cumulus. Thus, oocyte fertilizability was correlated to human cumulus cell (hCC) and human granulosa-lutein (G-L) cell competence for P4 secretion in culture. In the G-L cells, P4 secretion and percentage of cells manifesting 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity increased concurrently with the period of culture. In the hCC, however, P4 secretion decreased concurrently with elongation of the culture period, whereas the percentage of 3 beta-HSD-positive cells increased. In hCC corresponding to the fertilized oocytes, P4 accumulation in culture medium was 1.9-fold (P < 0.001) and 1.6-fold (P < 0.02) higher on days 0-3 and 3-5 of culture, respectively, as compared to P4 accumulation in hCC of unfertilized oocytes. Also, in hCC corresponding to the fertilized oocytes, the degree of 3 beta-HSD activity was found to be significantly higher shortly after aspiration and after either 3 or 5 days, compared to hCC of unfertilized oocytes. In the G-L cells pooled from all follicles yielding mature cumulus-oocyte complexes, P4 accumulation and percentage of 3 beta-HSD-positive cells increased concurrently with the increase in percentage of fertilized eggs of each individual woman. These results indicate that in stimulated cycles, follicles yielding mature cumulus-oocyte complex, oocyte fertilizability, and G-L cell or hCC competence for P4 secretion are correlated and synchronous.

3-Hydroxysteroid Dehydrogenases↗
PubMed2006

Oocyte-secreted factor activation of SMAD 2/3 signaling enables initiation of mouse cumulus cell expansion.

Expansion of the mouse cumulus-oocyte complex (COC) is dependent on oocyte-secreted paracrine factors. Transforming growth factor beta (TGFB) superfamily molecules are prime candidates for the cumulus expansion-enabling factors (CEEFs), and we have recently determined that growth differentiation factor 9 (GDF9) alone is not the CEEF. The aim of this study was to examine oocyte paracrine factors and their signaling pathways that regulate mouse cumulus expansion. Using RT-PCR, oocytes were found to express the two activin subunits, Inhba and Inhbb, and activin A and activin B both enabled FSH-induced cumulus expansion of oocytectomized (OOX) complexes. Follistatin, an activin-binding protein, neutralized activin-induced expansion but had no effect on oocyte-induced expansion. The type I receptors for GDF9 and activin are activin receptor-like kinase 5 (ALK5) and ALK4, respectively, both of which activate the same SMAD 2/3 signaling pathway. We examined the requirement for this signaling system using an ALK 4/5/7 inhibitor, SB-431542. SB-431542 completely ablated FSH-stimulated GDF9-, activin A-, activin B-, and oocyte-induced cumulus expansion. Moreover, SB-431542 also antagonized epidermal growth factor-stimulated, oocyte-induced cumulus expansion. Using real-time RT-PCR, SB-431542 also attenuated GDF9-, activin A-, and oocyte-induced OOX expression of hyaluronan synthase 2, tumor necrosis factor alpha-induced protein 6, prostaglandin synthase 2, and pentraxin 3. This study provides evidence that the CEEF is composed of TGFB superfamily molecules that signal through SMAD 2/3 to enable the initiation of mouse cumulus expansion.

Activin Receptors↗
PubMed1995

Regulation of cumulus cell steroidogenesis by the porcine oocyte and preliminary characterization of oocyte-produced factor(s).

This study was designed to investigate whether porcine oocytes produce a factor(s) that influences cumulus and mural granulosa cell steroid production and to characterize the biochemical nature and mode of action of a such factor(s). Porcine cumulus-oocyte complexes (COC) were collected from 2-5 mm follicles and cultured either intact or after oocytectomy for 48 h. Steroid levels were then measured in the culture media. Conditioned media, obtained by culturing denuded oocytes for 48 h, were subjected to heat treatment of charcoal extraction and utilized to culture intact and oocytectomized COC. FSH-stimulated progesterone, 20 alpha-OH-progesterone, and estradiol were significantly higher in oocytectomized vs. intact COC cultures. Denuded oocytes cultured with granulosa cells significantly inhibited progesterone production compared to control. Also, media conditioned with different numbers of denuded oocytes (0 to 300) significantly inhibited progesterone production by oocytectomized COC in a manner dependent on oocyte number. Charcoal extraction, but not heat treatment, significantly removed the inhibitory effect of the conditioned media on progesterone production by oocytectomized COC. Increased progesterone production by oocytectomized COC was not accompanied by a similar increase in cAMP formation. Heptanol, a gap junction blocker, did not alter progesterone production by intact COC. In conclusion, porcine oocytes secrete a factor(s) that inhibits cumulus and mural granulosa cell steroidogenesis. This factor(s) is heat stable but extractable by charcoal. The factor(s) appears not to be transferred to somatic cells via gap junctions, and its effect is downstream of cAMP formation.

Animals↗
PubMed2001

Cumulus cell contribution to cytoplasmic maturation and oocyte developmental competence in vitro.

OBJECTIVE: Although several reports indicated the bidirectional communication between the oocyte and granulosa cell, and the potential negative impact of premature cumulus removal, clinical data are controversial. The present analysis report the results of a prospective randomized study done on sibling oocytes to evaluate whether or not preincubation with intact cumulus is needed in ICSI. METHODS: It was a prospective randomized study, and conducted at Alexandria IVF-ICSI center. This study was performed using 926 M2 oocytes from 141 cycles of patients undergoing ICSI. Oocytes were randomized between three protocols: protocol A (immediate denudation, immediate injection), protocol B (delayed denudation, delayed injection), and protocol C (early denudation, delayed injection). Main outcome measure(s) were maturation, fertilization, and cleavage rate after ICSI. RESULTS: Aspects of nuclear, cytoplasmic maturation and oolemma properties were improved when oocytes were preincubated with intact cumulus before ICSI. CONCLUSIONS: Preincubation, before ICSI improved results. Duration of preincubation should be program specific.

Female↗
PubMed1988

Follicular factors influence oocyte fertilizability by modulating the intercellular cooperation between cumulus cells and oocyte.

In order to investigate whether the follicular tissue influences cumulus-oocyte interaction and, consequently, the fertilizability of the egg, four experiments were carried out. In the first, cumulus-enclosed pig oocytes were cultured for 44 h in control medium (modified TCM-199) or in follicle-conditioned medium, and the intercellular coupling was studied by measuring 3H-uridine uptake. In control medium the intercellular cooperation started to decline immediately, and at 24-32 h the uncoupling was almost complete. By contrast, in follicle, conditioned medium, it remained at high levels until 24-32 h. In the second experiment protein synthesis patterns of oocytes were studied. Oocytes cultured in conditioned medium were characterized by a 45-kD protein band, while those maturing in control medium were identifiable by a marked 56-kD band. In the third experiment mature oocytes were fertilized in vitro. The percentage of penetrated egg was higher in oocytes matured in conditioned medium than in control medium. In addition, only oocytes matured in conditioned medium could consistently decondense spermatozoa and form male pronuclei. Metabolic cooperation, protein synthesis patterns, and fertilizability were also studied in oocytes matured in control medium supplemented with either 17 beta-estradiol or progesterone or testosterone or dihydrotestosterone or androstenedione or ether extract of conditioned medium. Only ether extract and progesterone stimulated cumulus oocyte interaction and sperm decondensation. In the last experiment oocytes denuded at different stage of their maturation in conditioned medium were fertilized in vitro. The longer the eggs were cultured with the cumulus, the higher was their penetrability. Moreover, only oocytes denuded after 40 h of culture could, once fertilized, promote the formation of male pronuclei. These data demonstrate that follicular secretions are fundamental for the maintenance in vitro of a functional intercellular coupling between cumulus and oocyte, which is necessary for the egg to become penetrable by spermatozoa and to acquire the conditions required for the formation of male pronuclei.

Animals↗
PubMed2004

Development potential of transgenic somatic cell nuclear transfer embryos according to various factors of donor cell.

The present study was conducted to establish an efficient production system for bovine transgenic somatic cell nuclear transfer (SCNT) embryos, the effect of various conditions of donor cells including cell type, size, and passage number on the developmental competence of transgenic SCNT embryos were examined with their expression rates of a marker gene. An expression plasmid for human prourokinase was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human prourokinase target gene into a pcDNA3 plasmid. Three types of bovine somatic cells including two adult cells (cumulus cells and ear fibroblasts) and fetal fibroblasts were prepared and transfected with the expression plasmid using a liposomal transfection reagent, Fugene6, as a carrier. In Experiment 1, three types of bovine cells were transfected at passages 2 to 4, and then trypsinized and GFP-expressing cells were randomly selected and used for SCNT. Developmental competence and rates of GFP expression in bovine transgenic SCNT embryos reconstructed with cumulus cells were significantly higher than those from fetal and ear fibroblasts. In all cell types used, GFP expression rates of SCNT embryos gradually decreased with the progression of embryo development. In Experiment 2, the effect of passage number of cumulus cells in early (2 to 4) and late (8 to 12) passages was investigated. No significant differences in the development of transgenic SCNT embryos were observed, but significantly higher GFP expression was shown in blastocysts reconstructed with cumulus cells at early passage. In Experiment 3, different sizes of GFP-expressing transfected cumulus cells [large (>30 microm) or small cell (<30 microm)] at passages 2 to 4 were used for SCNT. A significant improvement in embryo development and GFP expression was observed when small cumulus cells were used for SCNT. Taken together, these results demonstrate that (1) adult somatic cells as well as fetal cells could serve as donor cells in transgenic SCNT embryo production and cumulus cells with small size at early passage were the optimal cell type, and (2) transgenic SCNT embryos derived from adult somatic cells have embryonic development potential.

Animals↗
PubMed1997

Effects of cumulus cells, different cryoprotectants, various maturation stages and preincubation before insemination on developmental capacity of frozen-thawed bovine oocytes.

To improve freezability of bovine follicular oocytes, it is necessary to minimize injury to the oocytes caused by freezing and the toxicity of cryoprotectants. The maturing ability of frozen-thawed follicular oocytes with or without cumulus complexes was tested. The proportion of frozen-thawed follicular oocytes reaching the metaphasc II (M II) stage after in vitro maturation of 24 h was significantly (P < 0.05) higher in cumulus oocyte complexes (COCs; 44%) than in denuded oocytes (30%). Oocytes were cultured for 0, 6, 12, 18 or 24 h then frozen-thawed with 1,2-propanediol (PROH) or dimethyl sulfoxide (DMSO), and cultured for 24, 18, 12, 6 or 0 h respectively. In PROH, 24:0 (67%) showed significantly (P < 0.05) higher maturation rate than 0:24 (38%), 6:18 (41%). In DMSO, 18:6 (72%) and 24:0 (61%) showed significantly (P < 0.05) higher maturation rate than 0:24 (30%), 6:18 (33%) and 12:12 (44%). In case of 18:6, DMSO (72%) showed significant (P < 0.05) higher maturation rate than PROH (52%), however in case of 0:24, 6:18, 12:12 and 24:0, there was no significant (P < 0.05) difference in the maturation rate between PROH and DMSO. The proportion of embryos developed to > or = 2 cell, > or = 8 cell, morula and blastocyst in 18:6 DMSO (35, 10, 3 and 0%) and 24:0 PROH (38, 12, 5 and 0%) was significantly (P < 0.05) lower than that of fresh oocytes (67, 38, 31 and 16%). There was no significant (P < 0.05) difference in the rate of embryos that developed to > or = 2 cells, > or = 8 cells, morulae and blastocysts between PROH and DMSO. When the frozen oocytes were grouped as rewarming culture (21:2 PROH) and control (24:0 PROH), there was no significant (P < 0.05) difference in the rate of embryos that developed to > or = 2 cells, > or = 8 cells, morulae and blastocysts between 24:0 PROH (42, 24, 11 and 1%) and 21:2 PROH (51, 29, 16 and 4%) but 21:2 PROH showed slightly higher developmental capacity than 24:0 PROH. Transferable blastocysts (4%) were obtained in 21:2 PROH when the frozen-thawed follicular oocytcs were fertilized and cultured for 8 to 9 d.

Journal Article↗
PubMed1997

Cumulus cell dispersal from murine oocytes by an epididymal guanidinobenzoatase.

Guanidinobenzoatase (GB), a serine proteinase with a molecular weight of 71,000, is found both free in the epididymal fluids of the mouse and bound to the sperm surface. Microgram quantities of the enzyme, purified from epididymal fluid, will completely disperse follicle cells from freshly ovulated oocytes after 15 min of incubation. Purified GB exhibits no hyaluronidase activity as determined by the acid albumin assay. The ability of GB to disperse follicle cells is blocked by a proteinase inhibitor endogenous to the male reproductive tract. The inhibitor has no effect on bovine testicular hyaluronidase. Although the function of GB has not been defined, the observations presented here indicate that it may play a role in cumulus matrix penetration during fertilization.

Animals↗
PubMed1999

Low chronic ethanol consumption affects ovulation and PGE synthesis by the cumulus cell masses in mice.

Central and gonadal function can be affected by chronic consumption of high and moderate doses of ethanol. Few studies have been conducted to determine the effect of ethanol intake at ovarian and gamete level. Previously, we showed that fertilization rates of low chronic ethanol treated female mice were diminished. Also, our recent results indicated that moderate chronic intake of ethanol by immature females could alter the ovulatory quantity and produce morphological alterations in the superovulated oocytes. Furthermore, PGE production by oocyte cumulus complexes (OCCs) was reduced in the females treated with 10% (w/v) ethanol. In the present investigation, we studied the effects of 5% ethanol treatment given to immature mice for 30 days on the quality and quantity of oocytes superovulated at 16 h posthuman chronic gonadotrophin. Treated females had impaired ovulation rates (P < 0.05) as compared to the controls. The percentage of activated and morphologically abnormal oocytes was elevated in the ethanol-treated females (P < 0.05). PGE synthesis by the OCCs was higher than in the controls (P < 0.01). In summary, the administration of long-term ethanol at a relatively low dose to immature females produces decreased ovulation rates, abnormal oocyte morphology with high spontaneous activation and altered levels of PGE production by the oocytes' cumulus complexes. The relationship between the oocyte quality and abnormal synthesis of PGE is discussed.

Animals↗
PubMed2003

Proliferation of donor mitochondrial DNA in nuclear transfer calves (Bos taurus) derived from cumulus cells.

In embryos derived by nuclear-transfer (NT), fusion of donor cell and recipient oocyte caused mitochondrial heteroplasmy. Previous studies from other laboratories have reported either elimination or maintenance of donor-derived mitochondrial DNA (mtDNA) from somatic cells in cloned animals. Here we examined the distribution of donor mtDNA in NT embryos and calves derived from somatic cells. Donor mitochondria were clearly observed by fluorescence labeling in the cytoplasm of NT embryos immediately after fusion; however, fluorescence diminished to undetectable levels at 24 hr after nuclear transfer. By PCR-mediated single-strand conformation polymorphism (PCR-SSCP) analysis, donor mtDNAs were not detected in the NT embryos immediately after fusion (less than 3-4%). In contrast, three of nine NT calves exhibited heteroplasmy with donor cell mtDNA populations ranging from 6 to 40%. These results provide the first evidence of a significant replicative advantage of donor mtDNAs to recipient mtDNAs during the course of embryogenesis in NT calves from somatic cells.

Animals↗
PubMed2001

Remodeling of donor nuclei, DNA-synthesis, and ploidy of bovine cumulus cell nuclear transfer embryos: effect of activation protocol.

The purpose of this study was to investigate the effects of two activation protocols on nuclear remodeling, DNA synthesis during the first cell cycle, chromosome segregation after first mitosis and development to blastocyst of embryos produced by somatic nuclear transfer. Pronuclear formation was significantly higher when activation lasted 5 hr compared to 3 hr for both ethanol-cycloheximide and ionomycin-bohemine treatment. However, the presence of a single nucleus was significantly higher in embryos activated for 3 hr in bohemine. Initiation of DNA synthesis was delayed in ethanol-cycloheximide group, however, after 12 hr labeling 100% of embryos synthesized DNA in both groups. Embryos activated with ethanol-cycloheximide developed to blastocysts at a significantly higher rate than those activated with ionomycin-bohemine. Analysis of 2-cell embryos with DNA probes for chromosome 6, 7, and 15 by fluorescence in situ hybridization showed that at least 50% of NT embryos were of normal ploidy independent of the activation stimulus. The results presented in this study show differences between the protocols compared on the nuclear events during the first cell cycle and on the development to blastocyst. Mol. Reprod. Dev. 59: 371-379, 2001.

Animals↗