scholarly journals Lack of FSH support enhances LIF–STAT3 signaling in granulosa cells of atretic follicles in cattle

Reproduction ◽  
2015 ◽  
Vol 150 (4) ◽  
pp. 395-403 ◽  
Author(s):  
Gustavo Freitas Ilha ◽  
Monique T Rovani ◽  
Bernardo G Gasperin ◽  
Alfredo Quites Antoniazzi ◽  
Paulo Bayard Dias Gonçalves ◽  
...  

Subordinate follicles (SFs) of bovine follicular waves undergo atresia due to declining FSH concentrations; however, the signalling mechanisms have not been fully deciphered. We used an FSH-induced co-dominance model to determine the effect of FSH on signalling pathways in granulosa cells of the second-largest follicles (SF in control cows and co-dominant follicle (co-DF2) in FSH-treated cows). The SF was smaller than DF in control cows while diameters of co-DF1 and co-DF2 in FSH-treated cows were similar. The presence of cleaved CASP3 protein confirmed that granulosa cells of SFs, but not of DFs and co-DFs, were apoptotic. To determine the effect of FSH on molecular characteristics of the second-largest follicles, we generated relative variables for the second largest follicle in each cow. For this, variables of SF or co-DF2 were divided by the variables of the largest follicle DF or co-DF1 in each cow. There was higher transcript abundance of MAPK1/3 and AKT1/2/3 but lower abundance of phosphorylated MAPK3/1 in SF than co-DF2 granulosa cells. Abundance of mRNA and phosphorylated protein of STAT3 was higher in granulosa cells of control SF than FSH-treated co-DF2. SF granulosa cells had higher levels of LIFR and IL6ST transcripts, the two receptors involved in STAT3 activation. Further, lower transcript abundance of interleukin 6 receptor (IL6R), another receptor involved in STAT3 activation, indicated that STAT3 activation in SF granulosa cells could be mainly due to leukemia inhibitory factor (LIF) signalling. These results indicate that atresia due to lack of FSH is associated with activated LIF–STAT3 signalling in SF granulosa cells, as FSH treatment reversed such activation.

2021 ◽  
pp. 1102-1108
Author(s):  
Ragab H. Mohamed ◽  
Amal M. Abo El-Maaty ◽  
Rasha S. Mohamed ◽  
Axel Wehrend ◽  
Fatma Ali ◽  
...  

Background and Aim: Estrus detection plays a crucial role in the success of animal reproduction. It was previously reported that body temperature changes during estrus. This study aimed to investigate the relationship between vaginal temperatures (VTs) measured by a data logger, ovarian activity, and hormonal cyclic changes in camels. Materials and Methods: Six mature, healthy, non-pregnant dromedary, and 10-12-year-old camels were included in the study. The ovarian activity was monitored with ultrasonography, and estrus behavior was evaluated using an active and virile male camel. Animals were inserted with a blank controlled internal drug release device attached with an intravaginal data logger. Every hour, the ambient temperature was recorded by another data logger. Blood samples were collected, and sera were used to measure estradiol and progesterone levels. Results: The whole follicular cycle lasted 25.41±1.36 days, and the maximum sizes of the dominant follicle in the first and second follicular waves were 1.63±0.27 cm and 1.94±0.42 cm, respectively. There was a significant positive correlation between the follicular diameter and estradiol-17β level (p<0.01, r=0.397). There was no correlation between the follicular diameter and progesterone level (p>0.05, r=0.038), which remained low during the whole period of the experiment. The mean daily VT was significantly correlated with the diameter of the dominant follicle (1.7-2.2 cm, p<0.01, r=0.52). Conclusion: Measurement of VT will improve the accuracy of estrus prediction. Further studies are recommended to validate VT in camel reproduction.


Author(s):  
Linah Al-Alem ◽  
Muraly Puttabyatappa ◽  
Ketan Shrestha ◽  
Yohan Choi ◽  
Kathy Rosewell ◽  
...  

Abstract Neurotensin (NTS) is a tridecapeptide that was first characterized as a neurotransmitter in neuronal cells. The present study examined ovarian NTS expression across the periovulatory period in the human and the rat. Women were recruited into this study and monitored by transvaginal ultrasound. The dominant follicle was surgically excised prior to the LH surge (preovulatory phase) or women were given 250 μg hCG and dominant follicles collected 12-18 h after hCG (early ovulatory), 18-34 h (late ovulatory) and 44-70 h (postovulatory). NTS mRNA was massively induced during the early and late ovulatory stage in granulosa cells (15,000 fold) and theca cells (700 fold). In the rat, hCG also induced Nts mRNA expression in intact ovaries and isolated granulosa cells. In cultured granulosa-lutein cells (GLC) from IVF patients, NTS expression was induced 6 h after hCG treatment whereas in cultured rat granulosa cells NTS increased 4 h after hCG treatment. Cells treated with hCG signaling pathway inhibitors revealed that NTS expression is partially regulated in the human and rat GC by the epidermal-like growth factor (EGF) pathway. Human GLC and rat granulosa cells also showed that Nts was regulated by the PKA pathway along with input from the PI3K and MAPK pathways. The predominate NTS receptor present in human and rat granulosa cells was SORT1, whereas NTSR1 and NTSR2 expression was very low. Based on NTS actions in other systems, we speculate that NTS may regulate crucial aspects of ovulation such as vascular permeability, inflammation, and cell migration.


2010 ◽  
Vol 22 (1) ◽  
pp. 299
Author(s):  
S. Matoba ◽  
S. Mamo ◽  
E. Gallagher ◽  
A. G. Fahey ◽  
T. Fair ◽  
...  

The ability to culture oocytes and embryos in an individually identifiable manner facilitates the study of the relationship between follicle param- eters and oocyte development, in order to identify markers of competent oocytes. The aim of this study was to examine the predictive value of intrafollicular steroid concentrations and granulosa cell transcript abundance on the ability of immature bovine oocytes to develop to the blastocyst stage in vitro. Individual follicles (n = 214, 11 replicates, 49 animals) were dissected from the ovaries of slaughtered animals. Following measure- ment of diameter, follicles were carefully ruptured under a stereomicroscope and the oocyte was recovered and individually processed through maturation, fertilization, and culture on the cell adhesive Cell-Tak (20 oocytes/100 μL; Matoba and Lonergan 2009 Reprod. Fertil. Dev. 21, 160). Cleavage and blastocyst rates were assessed on Days 2 and 9, respectively. Follicular fluid was recovered and stored at -80°C until analysis for concentrations of the steroids estradiol, progesterone, and testosterone by RIA. Granulosa cells were collected from each follicle for analysis of gene expression by quantitative RT-PCR. Primers were designed for 7 target genes (AMH, CYP19A, ESR1, ESR2, FSHR, HSD3B1 and LHCGR) and 2 reference genes (PPIA and H2AZ). Transcript abundance of target genes in granulosa cells associated with embryos that cleaved and developed to the blastocyst stage (competent) and those that cleaved but failed to develop (incompetent) was examined. Mean steroid concentrations were compared by ANOVA and Spearman correlations, and logistical regression were used to test the relationship between follicle size and steroid con- centration and the ability of steroid concentration to predict developmental competence. Gene expression data were analyzed using the delta-delta CT (cycle threshold) method. Values were normalized to the average values of the reference genes and means were compared by the Student’s t-test In total, 79.1% of oocytes cleaved after IVF and 28.3% developed to the blastocyst stage. The mean (±SEM) follicular concentrations of testosterone (62.8 ± 4.8 ng mL-1), progesterone (616.8 ± 31.9 ng mL-1), or estradiol (14.4 ± 2.4 ng mL-1 were not different (P ≥ 0.05) between competent and incompetent oocytes. Follicular diameter was negatively correlated with testosterone, progesterone, testosterone:estradiol, and pro- gesterone:estradiol (P ≤ 0.01) and positively correlated with estradiol (P ≤ 0.01). Logistical regression analysis showed that steroid concentrations or the ratio of steroids were not satisfactory predictors of oocyte competence. Transcript abundance of AMH, ESR1, ESR2, FSHR, and HSD3B1 was significantly higher (P ≤ 0.05) in granulosa cells associated with competent compared with incompetent oocytes. In conclusion, follicular steroid concentrations were not associated with oocyte development. In contrast, granulosa cell gene expression may be a useful predictor of oocyte competence. Supported by Science Foundation Ireland (07/SRC/B1156).


2009 ◽  
Vol 21 (1) ◽  
pp. 187 ◽  
Author(s):  
C. M. Barros ◽  
R. L. Ereno ◽  
M. F. Machado ◽  
J. Buratini ◽  
M. F. Pegorer ◽  
...  

During bovine follicular development, there is a phase known as follicular deviation in which the future dominant follicle grows faster than the other follicles and acquires LH receptors (LHR). In Nellore breed, deviation occurs 2.5 days after ovulation, and at this time, the dominant follicle has in average a diameter of 6.0 mm. Some authors believe that LHRs are present in the future dominant follicle before deviation and are essential for this process. However, others are convinced that LHRs are present only during or after follicular deviation. The aim of the present experiment was to evaluate the expression of 4 LHR isoforms (M1 to M4) in granulosa cells of follicles from Nellore heifers before, during, and after follicular deviation. At a random stage of the estrous cycle (D0), Nellore heifers (n = 21) received a progesterone intravaginal device (1.0 g, Primer®, Tecnopec, Sao Paulo, Brazil) and 2.5 mg of estradiol benzoate (EB, i.m., Estrogin®, Farmavet, Sao Paulo, Brazil). Eight days later (D8) PGF2α was administered (150 μg d-cloprostenol, i.m., Prolise®, ARSA S.R.L., Buenos Aires, Argentina), and the device was removed. Twenty-four hours after device removal, cows were treated with EB (1.0 mg, i.m.), and from this point in time, the growth of the dominant follicle growth was observed by ultrasonography (US, Aloka 900, Tokyo, Japan) every 12 h. The animals were allocated in 3 groups: Group 2 (G2, 2 days after ovulation, n = 7), Group 2.5 (G2.5, 2.5 days after ovulation, n = 7), and Group 3 (G3, 3 days after ovulation, n = 7), and were slaughtered 2, 2.5, and 3 days after ovulation, respectively, in order to remove the ovaries. The granulosa cells, obtained from ovarian follicles, were separated for total RNA extraction, and the gene expression of LHR isoforms was measured by semiquantitative RT-PCR. Since LHR expression was not detected in Group 2 (follicles with 4.5 to 6.7 mm), comparisons were performed between groups G2.5 and G3 by ANOVA. The LHR expression was detected only in 2 samples of Group G2 (7.0-mm follicles) and was significantly higher in Group G3 (63.6%; follicles from 8 to 14 mm, P < 0.05). In all samples that expressed LHR, the 4 isoforms were present. It is concluded that LHR expression is present in granulosa cells of follicles from Nellore heifers after follicular deviation. Support and fellowship from FAPESP (Sao Paulo, Brazil).We are grateful to Tecnopec (Sao Paulo, Brazil) for providing intravaginal devices used in the experiment.


2009 ◽  
Vol 21 (9) ◽  
pp. 108
Author(s):  
R. A. Keightley ◽  
B. Nixon ◽  
S. D. Roman ◽  
D. L. Russell ◽  
R. L. Robker ◽  
...  

Follicular development requires the recruitment of primordial follicles into the growing follicle pool following initiation of multiple cytokine signalling pathways. Suppression of follicular development is thought to be key to maintaining the population of primordial follicles and allowing for controlled release of these follicles throughout the reproductive lifespan of the female. However, little is known of the processes and signalling molecules that suppress primordial follicle activation and early follicle growth. Our group has identified significant upregulation of the Janus Kinase 2 (JAK2)/ Signal Transducer and Activator of Transcription 3 (STAT3) signalling pathway inhibitor the Suppressor of Cytokine Signalling 4 (SOCS4) that coincides with the initial wave of follicular activation in theneonatal mouse ovary. Further studies by our group have localised the SOCS4 protein to the granulosa cells of activating and growing follicles, suggesting SOCS4 expression may be linked to follicular activation. We have focused on examining protein localisation and gene expression patterns of the eight SOCS family members CIS and SOCS1-7. We have recently demonstrated that co-culture of neonatal ovaries with Kit Ligand (KL) for 2 days increases the mRNA levels of all SOCS genes. We also demonstrated the co-localisation of SOCS2 proteins with the KL receptor c-kit in the mural granulosa cells of antral, and large pre-antral follicles suggesting a significant role for SOCS2 in the later stages of follicular development. We have also shown that culturing ovaries with the potent JAK2 inhibitor AG490 substantially reduces mRNA levels of all SOCS and STAT genes that we have so far measured. We hypothesise a significant role for JAK2/STAT3 signalling in promoting the activation and early growth of ovarian follicles. Our investigations have identified significant roles for JAK2/STAT3 and the SOCS family in the regulation of ovarian follicle development.


2012 ◽  
Vol 87 (Suppl_1) ◽  
pp. 504-504 ◽  
Author(s):  
Annie Gagnon ◽  
Marc-André Sirard ◽  
François Richard ◽  
Jean-Paul Laforest

Reproduction ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 95-106 ◽  
Author(s):  
Osman V Patel ◽  
Anilkumar Bettegowda ◽  
James J Ireland ◽  
Paul M Coussens ◽  
Patrick Lonergan ◽  
...  

Poor oocyte competence contributes to infertility in humans and livestock species. The molecular characteristics of such oocytes are generally unknown. Objectives of the present studies were to identify differences in RNA transcript abundance in oocytes and early embryos associated with reduced oocyte competence and development to the blastocyst stage. Microarray experiments were conducted using RNA isolated from germinal vesicle stage oocytes collected from adult versus prepubertal animals (model of poor oocyte competence). A total of 193 genes displaying greater mRNA abundance in adult oocytes and 223 genes displaying greater mRNA abundance in prepubertal oocytes were detected. Subsequent gene ontology analysis of microarray data revealed significant overrepresentation of transcripts encoding for genes in hormone secretion classification within adult oocytes and such genes were selected for further analysis. Real-time PCR experiments revealed greater abundance of mRNA for βA and βB subunits of inhibin/activin and follistatin, but not the α subunit in germinal vesicle stage oocytes collected from adult versus prepubertal animals. Cumulus cell follistatin and βB subunit mRNA abundance were similar in samples collected from prepubertal versus adult animals. A positive association between time of first cleavage (oocyte competence) and follistatin mRNA abundance was noted. Follistatin, βB, and α subunit mRNAs were temporally regulated during early bovine embryogenesis and peaked at the 16-cell stage. Collectively, results demonstrate a positive association of follistatin mRNA abundance with oocyte competence in two distinct models and dynamic regulation of follistatin, βB, and α subunit mRNAs in early embryos after initiation of transcription from the embryonic genome.


1993 ◽  
Vol 73 (2) ◽  
pp. 267-275 ◽  
Author(s):  
G. P. Adams ◽  
K. Kot ◽  
C. A. Smith ◽  
O. J. Ginther

The relationship between a dominant follicle of a follicular wave and the suppression of subordinate follicles was studied during the first postovulatory wave (Wave 1) in Holstein heifers. The dominant follicle (largest follicle) was cauterized or a sham-operation was done on day 3 (day 0 = ovulation) using seven heifers per group. In the cautery group, compared to the controls, the largest subordinate follicle attained a larger diameter (11 7 vs 8 0 mm; P < 0.01), reached maximum diameter at a later day (day 9.2 vs. day 3.1; P < 0 01) and began to regress at a later day (day 14.3 vs. day 5.7; P < 0.01). In addition, the emergence of Wave 2 was hastened (day 6.4 vs. day 9.3; P < 0.05) and more heifers had more than two waves per interovulatory interval (5 of 6 vs. 2 of 7; P < 0.05). In heifers with the dominant follicle eliminated, the largest subordinate grew to the diameter of a dominant follicle during Wave 1 (n = 3) or became the dominant follicle of a newly emerged wave (n = 2). A subordinate sometimes persisted as a small follicle (e.g., 5 mm) for several days before resurging. However, it was not convincingly demonstrated that a subordinate follicle could resurge after it had begun to regress (decrease in diameter). Results supported the hypothesis that suppression of subordinate follicles is a prolonged process, so that resurgence of a subordinate can occur if the dominant follicle is removed. Key words: Ovaries, follicular waves, selection, cattle, cauterization


2019 ◽  
Vol 54 (5) ◽  
pp. 741-749 ◽  
Author(s):  
Dejun Xu ◽  
Huanshan He ◽  
Xiaohan Jiang ◽  
Lulu Yang ◽  
Dinbang Liu ◽  
...  

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