scholarly journals Tribbles Pseudokinase 2 (TRIB2) Regulates Expression of Binding Partners in Bovine Granulosa Cells

2021 ◽  
Vol 22 (4) ◽  
pp. 1533
Author(s):  
Aly Warma ◽  
Jacques G. Lussier ◽  
Kalidou Ndiaye

Members of the Tribbles (TRIB) family of pseudokinases are critical components of intracellular signal transduction pathways in physiological and pathological processes. TRIBs, including TRIB2, have been previously shown as signaling mediators and scaffolding proteins regulating numerous cellular events such as proliferation, differentiation and cell death through protein stability and activity. However, the signaling network associated with TRIB2 and its binding partners in granulosa cells during ovarian follicular development is not fully defined. We previously reported that TRIB2 is differentially expressed in growing dominant follicles while downregulated in ovulatory follicles following the luteinizing hormone (LH) surge or human chorionic gonadotropin (hCG) injection. In the present study, we used the yeast two-hybrid screening system and in vitro coimmunoprecipitation assays to identify and confirm TRIB2 interactions in granulosa cells (GCs) of dominant ovarian follicles (DFs), which yielded individual candidate binding partners including calmodulin 1 (CALM1), inhibin subunit beta A (INHBA), inositol polyphosphate phosphatase-like 1 (INPPL1), 5′-nucleotidase ecto (NT5E), stearoyl-CoA desaturase (SCD), succinate dehydrogenase complex iron sulfur subunit B (SDHB) and Ras-associated protein 14 (RAB14). Further analyses showed that all TRIB2 binding partners are expressed in GCs of dominant follicles but are differentially regulated throughout the different stages of follicular development. CRISPR/Cas9-driven inhibition along with pQE-driven overexpression of TRIB2 showed that TRIB2 differently regulates expression of binding partners, which reveals the importance of TRIB2 in the control of gene expression linked to various biological processes such as proliferation, differentiation, cell migration, apoptosis, calcium signaling and metabolism. These data provide a larger view of potential TRIB2-regulated signal transduction pathways in GCs and provide strong evidence that TRIB2 may act as a regulator of target genes during ovarian follicular development.

Reproduction ◽  
2010 ◽  
Vol 140 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Kenneth P McNatty ◽  
Derek A Heath ◽  
Norma L Hudson ◽  
Karen L Reader ◽  
Laurel Quirke ◽  
...  

In mammals with a low ovulation rate phenotype, ovarian follicular development is thought to be hierarchical with few, if any, antral follicles at similar stages of development. The hypothesis being tested herein was that if most follicles are in a functionally different state, then the application of exogenous hormones to increase ovulation rate will not overcome the hierarchical nature of follicular development. Using sheep as the experimental model, the functional states of all non-atretic antral follicles ≥2 mm diameter were assessed in individual ewes (N=10/group) during anoestrus with or without pregnant mare's serum gonadotrophin (PMSG) treatment, or after a standard superovulation regimen, or during the follicular phase of the oestrous cycle. The functional states of these follicles were assessed by measuring the FSH- or human chorionic gonadotrophin (hCG)-induced cAMP responses of granulosa cellsin vitro. There were significant overall effects across the treatment groups on the responses of granulosa cells to either FSH or LH (bothP<0.001). It was concluded that for anoestrous ewes with or without PMSG treatment, and ewes during the follicular phase, granulosa cell populations of many follicles (≥2 mm diameter) did not share a similar cAMP response to FSH (∼50% of follicles) or hCG (>90% of follicles) either on a per cell or total cell basis. After superovulation, ≤30 and 10% respectively of the granulosa cell populations shared similar responses to FSH and LH with regard to follicular diameter and cAMP output. Thus, exogenous hormone treatments used routinely for increasing oocyte yield do not effectively override the hierarchical pattern of ovarian follicular development during the follicular phase.


Author(s):  
Ming Li ◽  
Ling Xue ◽  
Weibin Xu ◽  
Pingping Liu ◽  
Feng Li

AbstractThe mechanism related to ovarian follicular is complex, which has not been fully elucidated. Abundant reports have confirmed that the ovarian function development is closely related to sympathetic innervation. As one of the major neurotransmitters, norepinephrine (NE) is considered an effective regulator of ovarian functions like granulosa cell (GC) apoptosis. However, the mechanism between NE and GC apoptosis in rat is still unclear. In our study, GCs were isolated and cultured in vitro with NE treatment. The apoptosis of GCs was facilitated by NE. Wilms tumor 1 (WT1) was found to be significantly downregulated in GCs after NE treatment, and overexpression of WT1 repressed apoptosis in rat GCs induced by NE. rno-miR-128-3p was found to be significantly enhanced by NE in GCs, and inhibition of rno-miR-128-3p repressed apoptosis in rat GCs induced by NE. Mechanistically, rno-miR-128-3p interacted with WT1 and repressed its expression. In summary, inhibition of rno-miR-128-3p may enhance WT1 expression, and then repress NE-induced apoptosis in rat GCs. Our research may provide a new insight for the improvement of ovarian follicular development.


Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 641-649 ◽  
Author(s):  
Inger B Carlsson ◽  
Mika P E Laitinen ◽  
Jennifer E Scott ◽  
Henna Louhio ◽  
Louiza Velentzis ◽  
...  

The receptor tyrosine c-Kit and its cognate ligand, c-Kit ligand (KL, stem cell factor, SCF), are involved in ovarian follicular development in several animal species. We studied the expression of KL and c-Kit usingin situhybridization and immunohistochemistry in donated human ovarian cortical tissue. The KL transcripts were expressed in granulosa cells of primary follicles, whereas the expression of c-Kit was confined to the oocyte and granulosa cells in primary and secondary follicles. We employed an ovarian organ culture using firstly serum-containing and then serum-free medium to study the effects of KL and an anti-c-Kit antibody, ACK2, on the development and survival of ovarian folliclesin vitro. Culture of ovarian cortical slices for 7 days resulted in a 37% increase in the number of primary follicles and a 6% increase in secondary follicles. The proportion of viable follicles decreased in all cultures. The addition of KL (1, 10 and 100 ng/ml) into the culture media did not affect the developmental stages of the follicles or the proportion of atretic follicles. Inclusion of ACK2 (800 ng/ml) in the culture medium significantly increased the proportion of atretic follicles on days 7 (49 vs 28% in control cultures) and 14 (62 vs 38%) of culture. In conclusion, c-Kit and KL are expressed in human ovaries during follicular development. Blocking the c-Kit receptor induces follicular atresia. The KL/c-Kit signaling system is likely to control the survival of human ovarian follicles during early follicular development.


Reproduction ◽  
2020 ◽  
Author(s):  
Xiaolei Yao ◽  
EI-Samahy M.a. ◽  
Shenhua Xiao ◽  
Zhibo Wang ◽  
Fanxing Meng ◽  
...  

Being a novel target of luteinizing hormone (LH), the effect of CREB-binding protein/P300-interacting trans-activator with ED-rich tail member 4 (CITED4) gene on the proliferation, apoptosis, and steroidogenesis of ovarian granulosa cells (GCs) in Hu sheep was investigated. The presence of CITED4, CREB-binding protein (CBP), CCAAT/enhancer binding protein alpha (C/EBPα) and -beta (C/EBPβ) proteins was demonstrated in GCs and luteal cells. CITED4 protein in GCs was induced by LH, and CITED4 overexpression moderately increased GC responses to LH. In contrast, CITED4 knockdown in GCs decreased prostaglandin (PGE2)-induced LH target genes levels. Moreover, PGE2-stimulated CITED4 mRNA expression was blocked by ERK1/2 inhibition (U0126), suggesting that CITED4 is a downstream target of the ERK1/2 pathway in sheep GCs. In contrast to CITED4 knockdown, CITED4 overexpression promoted GC proliferation, inhibited apoptosis, upregulated cell cycle-related genes, and downregulated apoptosis-related genes. Additionally, CITED4 overexpression induced cell cycle transition from S to G2/M phase. No effect was observed with CITED4 knockdown. CITED4 overexpression increased progesterone (P4) production levels and StAR mRNA expression, whereas CITED4 knockdown decreased P4 production and StAR and 3β-HSD mRNA expression levels. Thus, our results suggest that CITED4 is involved in regulating the expression of LH-induced genes and the ERK1/2 pathway and the proliferation, apoptosis, and steroidogenesis in Hu sheep GCs by modulating the expression of related genes. These findings will help understand the role of CITED4 in follicular development and ovulation of pre-ovulatory follicles.


Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. 73-80 ◽  
Author(s):  
JongYeob Choi ◽  
MinWha Jo ◽  
EunYoung Lee ◽  
DooSeok Choi

In this study, we examined whether granulosa cell autophagy during follicular development and atresia was regulated by the class I phosphoinositide-3 kinase/protein kinase B (AKT) pathway, which is known to control the activity of mammalian target of rapamycin (mTOR), a major negative regulator of autophagy. Ovaries and granulosa cells were obtained using an established gonadotropin-primed immature rat model that induces follicular development and atresia. Autophagy was evaluated by measuring the expression level of microtubule-associated protein light chain 3-II (LC3-II) using western blots and immunohistochemistry. The activity of AKT and mTOR was also examined by observing the phosphorylation of AKT and ribosomal protein S6 kinase (S6K) respectively. After gonadotropin injection, LC3-II expression was suppressed and phosphorylation of AKT and S6K increased in rat granulosa cells. By contrast, gonadotropin withdrawal by metabolic clearance promoted LC3-II expression and decreased phosphorylation of AKT and S6K. In addition,in-vitroFSH treatment of rat granulosa cells also indicated inhibition of LC3-II expression accompanied by a marked increase in phosphorylation of AKT and S6K. Inhibition of AKT phosphorylation using AKT inhibitor VIII suppressed FSH-mediated phosphorylation of S6K, followed by an increase in LC3-II expression. Furthermore, co-treatment with FSH and AKT inhibitor increased the levels of apoptosis and cell death of granulosa cells compared with the single treatment with FSH. Taken together, our findings indicated that AKT-mediated activation of mTOR suppresses granulosa cell autophagy during follicular development and is involved in the regulation of apoptotic cell death.


1997 ◽  
Vol 18 (1) ◽  
pp. 27-35 ◽  
Author(s):  
G N Europe-Finner ◽  
E Cartwright ◽  
J Bellinger ◽  
H J Mardon ◽  
D H Barlow ◽  
...  

ABSTRACT Granulosa cells are essential for follicular development and corpus luteum formation and their functions are regulated by gonadotrophins through G protein-coupled receptors. The dominant second messenger pathway involves the stimulation of cyclic AMP formation by Gαs-linked receptors. In this paper we have investigated the expression of Gαs mRNA splice variants in relation to expression of Gαs protein isoforms in granulosa cells obtained from patients undergoing in vitro fertilization. We have carried out ribonuclease protection assays using cRNA riboprobes which are capable of detecting all Gαs mRNA isoforms as well as quantifying total amounts of Gαs mRNA. Granulosa cells express the message for Gαs-Large and Gαs-Small and the presence of two distinct protein products was confirmed by immunoblotting using the antibody RM/1. Moreover, the data show that a significant fraction of Gαs-Large and Gαs-Small mRNAs contain an extra CAG codon. This should generate proteins with an extra serine residue, resulting in Gαs variants with the consensus sequence of a protein kinase C phosphorylation site. These results highlight the possible interaction between different signalling pathways in the control of cAMP production and the need to investigate the relationship between Gαs variants and different adenylyl cyclase isozymes in patients with normal and abnormal ovarian function.


1992 ◽  
Vol 263 (5) ◽  
pp. E943-E949 ◽  
Author(s):  
S. Y. Hsu ◽  
F. W. Goetz

The present study investigated the effects of a number of oxoanion compounds on in vitro ovulation of goldfish follicles and ovarian second messenger activities. Significant levels of ovulation were induced by 0.1 mM sodium chromate, 0.1 mM sodium metavanadate, 10 mM sodium molybdate, 0.1 mM sodium orthovanadate, 5 mM sodium selenate, 0.5 mM sodium tungstate, and 0.1 mM vanadyl sulfate. At levels that significantly stimulated ovulation, metavanadate, molybdate, orthovanadate, tungstate, and vanadyl sulfate also stimulated follicular phosphatidylinositol cycling and inhibited ovarian alkaline phosphatase activity. Moreover, the ovulation induced by these oxoanions was not inhibited by indomethacin (10 micrograms/ml), while ovulation induced by selenate and chromate was. In contrast, only vanadium-containing compounds significantly stimulated prostaglandin (PG) synthesis, and, in fact, selenate significantly inhibited PG production. Finally, only sodium molybdate- and vanadium-containing compounds appeared to increase follicular adenosine 3',5'-cyclic monophosphate content. While all oxoanions stimulated in vitro ovulation, they had differential effects on certain signal transduction pathways when tested at concentrations that stimulated in vitro ovulation. From the results, two basic groups could be delineated, one containing tungstate-, molybdate-, and vanadium-containing compounds and the other selenate and chromate. Thus the mechanism by which ovulation is induced by chromate and selenate may be different from that of vanadium-containing compounds, molybdate, and tungstate.(ABSTRACT TRUNCATED AT 250 WORDS)


2019 ◽  
Vol 102 (2) ◽  
pp. 511-520
Author(s):  
Yanrong Kuai ◽  
Xiaobo Gao ◽  
Huixia Yang ◽  
Haiyan Luo ◽  
Yang Xu ◽  
...  

Abstract Pentachloronitrobenzene (PCNB) is an organochlorine fungicide widely used for crop production and has become an environmental concern. Little is known about the effect of PCNB on ovarian steroidogenesis and follicular development. We found that PCNB stimulated Star expression and progesterone production in cultured rat granulosa cells in a dose-dependent manner. PCNB activated mitogen-activated protein kinase (MAPK3/1) extracellulat regulated kinase (ERK1/2), thus inhibition of either protein kinase A (PKA) or MAPK3/1 signaling pathway significantly attenuated progesterone biosynthesis caused by PCNB, suggesting that PCNB induced progesterone production by activating the cyclic adenosine monophosphate (cAMP/PKA) and MAPK3/1 signaling pathways. Further investigation demonstrated that PCNB induced Star expression and altered MAPK3/1 signaling in ovary tissues of immature SD rats treated with PCNB at the dose of 100, 200, or 300 mg/kg by daily gavage for 7 days, while serum progesterone level was dose-dependently decreased. We demonstrated that PCNB exposure accelerated the recruitment of primordial follicles into the growing follicle pool in ovary tissues, accompanied by increased levels of anti-Mullerian hormone (AMH) in both ovary tissues and serum. Taken together, our data demonstrate for the first time that PCNB stimulated Star expression, altered MAPK3/1 signaling and progesterone production in vivo and in vitro, and accelerated follicular development with a concomitant increase in AMH in ovary tissues and serum. Our findings provide novel insight into the toxicity of PCNB to animal ovary function.


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