scholarly journals Gene expression profiling of bovine preovulatory follicles: gonadotropin surge and prostanoid-dependent up-regulation of genes potentially linked to the ovulatory process

Reproduction ◽  
2009 ◽  
Vol 137 (2) ◽  
pp. 297-307 ◽  
Author(s):  
Qinglei Li ◽  
Fermin Jimenez-Krassel ◽  
James J Ireland ◽  
George W Smith

The molecular mechanisms of ovulation and luteinization have not been well established, partially due to lack of a comprehensive understanding of functionally significant genes up-regulated in response to an ovulatory stimulus and the signaling pathways involved. In the present study, transcripts increased in bovine preovulatory follicles following a GnRH-induced LH surge were identified using microarray technology. Increased expression of 368 and 878 genes was detected at 12 (368 genes) and 20 h (878 genes) following GnRH injection. The temporal, cell specific and prostanoid-dependent regulation of selected genes (ADAM10,DBI,CD36,MTSS1,TFG, andRABGAP1) identified from microarray studies and related genes (ADAM17andAREG) of potential significance were also investigated. Expression of mRNA forDBIandCD36was simultaneously up-regulated in theca and granulosa cells (GC) following the LH surge, whereas temporal regulation ofADAM10,MTSS1,TFG, andRABGAP1was distinct in the two cell compartments and increased granulosaTFGandRABGAP1mRNA were prostanoid dependent.AREGmRNA was increased in theca and GCs at 12 and 24 h following GnRH injection.ADAM17mRNA was increased in theca, but reduced in GCs 24 h following GnRH injection. The increasedADAM17andAREGmRNA were prostanoid dependent. ADAM10 and ADAM17 protein were increased specifically in the apex but not the base of preovulatory follicles and the increase in ADAM17 was prostanoid dependent. Results reveal novel information on the regulation of preovulatory gene expression and suggest a potential functional role for ADAM10 and ADAM17 proteins in the region of follicle rupture.

Author(s):  
Alexander A. Tokmakov ◽  
Vasily E. Stefanov ◽  
Ken-Ichi Sato

Ovulation is a unique physiological phenomenon that is essential for sexual reproduction. It refers to the entire process of ovarian follicle responses to hormonal stimulation resulting in the release of mature fertilization-competent oocytes from the follicles and ovaries. Remarkably, ovulation in different species can be reproduced out-of-body with high fidelity. Moreover, most of the molecular mechanisms and signaling pathways engaged in this process have been delineated using in vitro ovulation models. Here, we provide an overview of the major molecular and cytological events of ovulation observed in frogs, primarily in the African clawed frog Xenopus laevis, using mainly ex vivo approaches, with the focus on meiotic oocyte maturation and follicle rupture. For the purpose of comparison and generalization, we also refer extensively to ovulation in other biological species, most notoriously, in mammals.


Reproduction ◽  
2009 ◽  
Vol 138 (1) ◽  
pp. 115-129 ◽  
Author(s):  
Francois Paradis ◽  
Susan Novak ◽  
Gordon K Murdoch ◽  
Michael K Dyck ◽  
Walter T Dixon ◽  
...  

This study aimed to describe the abundance and localization ofBMP2,BMP6,BMP15,GDF9,BMPR1A,BMPR1B,BMPR2andTGFBR1mRNA during pig preovulatory follicular development and to evaluate their implication in improving follicular maturity in the preovulatory period preceding the second versus first post-weaning oestrus. Oocytes, granulosa (GC) and theca cells (TC) were recovered from antral follicles of primiparous sows at day 1, 2 and 4 after weaning and at day 14, 16 and 20 of their subsequent oestrous cycle. Real-time PCR analysis revealed that with the exception ofBMP6mRNA, which was absent in GC, all genes were expressed in every cell type. AlthoughBMP6,BMP15andGDF9mRNA were most abundant in the oocyte, their expression remained relatively constant during follicular development. By contrast, receptorBMPR1BandTGFBR1expressions in the GC and TC were temporally regulated.BMPR1BmRNA abundance was positively correlated with plasma oestradiol (E2) suggesting that its regulation by oestrogen may be implicated in normal folliculogenesis. Interestingly, the increase inBMPR1BmRNA and protein abundance during the periovulatory period in GC and TC suggests a role for bone morphogenetic protein (BMP) 15 in the ovulatory process. Finally, expression of these ligands and receptors was not associated with potential differences in follicle maturity observed during the second versus first post-weaning preovulatory follicular wave. In conclusion, our results clearly demonstrate the presence of a complex signalling system within the pig follicle involving the transforming growth factor-β superfamily and their receptors, and provide evidence to support a role for BMP15 and BMPR1B during ovulation.


2008 ◽  
Vol 28 (5) ◽  
pp. 1770-1782 ◽  
Author(s):  
Jaeyeon Kim ◽  
Marcey Sato ◽  
Quanxi Li ◽  
John P. Lydon ◽  
Francesco J. DeMayo ◽  
...  

ABSTRACT The progesterone receptor (PR) plays a critical role during ovulation. Mice lacking the PR gene are anovulatory due to a failure in the rupture of the preovulatory follicles. The pathways that operate downstream of PR to control ovulation are poorly understood. Using gene expression profiling, we identified peroxisome proliferator-activated receptor γ (PPARγ) as a target of regulation by PR in the granulosa cells of the preovulatory follicles during the ovulatory process. To investigate the function of PPARγ during ovulation, we created a conditional knockout mouse in which this gene was deleted via Cre-Lox-mediated excision in granulosa cells. When these mutant mice were subjected to gonadotropin-induced superovulation, the preovulatory follicles failed to rupture and the number of eggs released from the mutant ovaries declined drastically. Gene expression analysis identified endothelin-2, interleukin-6, and cyclic GMP-dependent protein kinase II as novel targets of regulation by PPARγ in the ovary. Our studies also suggested that cycloxygenase 2-derived metabolites of long-chain fatty acids function as endogenous activating ligands of PPARγ in the preovulatory follicles. Collectively, these studies revealed that PPARγ is a key mediator of the biological actions of PR in the granulosa cells and activation of its downstream pathways critically controls ovulation.


Reproduction ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 555-564 ◽  
Author(s):  
Qinglei Li ◽  
Leanne J Bakke ◽  
J Richard Pursley ◽  
George W Smith

The matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are potential regulators of the focalized extracellular matrix degradation required for ovulation. The objectives of the present study were to determine localization and temporal regulation of TIMP-3 and TIMP-4 mRNA and protein in bovine preovulatory follicles. Ovaries containing preovulatory follicles were collected at 0, 12 and 20 h after GnRH injection for real-time PCR quantification of TIMP-3 and TIMP-4 mRNAs and immunohistochemical localization studies. Additional samples collected at 0, 6, 12, 18 and 24 h post GnRH injection were subjected to Western analysis to determine temporal changes in TIMP-3 and TIMP-4 proteins in the apex and base of preovulatory follicles. Results indicate the gonadotropin surge regulates TIMP-3 and TIMP-4 expression. TIMP-3 and TIMP-4 mRNAs increased within 12 h after GnRH injection. TIMP-3 protein was localized to granulosal and thecal layers of preovulatory follicles and adjacent ovarian stroma, whereas TIMP-4 immunoreactivity was localized to granulosal and thecal cells and ovarian blood vessels. Amounts of TIMP-3 and TIMP-4 proteins in the follicular apex peaked within 12 h post GnRH injection and subsequently declined by 24 h. However, amounts of TIMP-3 and TIMP-4 proteins in the base were not elevated after GnRH administration. Results demonstrate that mRNA and protein for both TIMP-3 and TIMP-4 are increased in bovine preovulatory follicles following the gonadotropin surge. Coordinate expression of TIMPs and MMPs may help regulate the extracellular matrix remodeling characteristic of the ovulatory process.


2011 ◽  
Vol 43 (19) ◽  
pp. 1105-1116 ◽  
Author(s):  
Amanda H. Mortensen ◽  
James W. MacDonald ◽  
Debashis Ghosh ◽  
Sally A. Camper

Mutations in the transcription factors PROP1 and PIT1 (POU1F1) lead to pituitary hormone deficiency and hypopituitarism in mice and humans. The dysmorphology of developing Prop1 mutant pituitaries readily distinguishes them from those of Pit1 mutants and normal mice. This and other features suggest that Prop1 controls the expression of genes besides Pit1 that are important for pituitary cell migration, survival, and differentiation. To identify genes involved in these processes we used microarray analysis of gene expression to compare pituitary RNA from newborn Prop1 and Pit1 mutants and wild-type littermates. Significant differences in gene expression were noted between each mutant and their normal littermates, as well as between Prop1 and Pit1 mutants. Otx2, a gene critical for normal eye and pituitary development in humans and mice, exhibited elevated expression specifically in Prop1 mutant pituitaries. We report the spatial and temporal regulation of Otx2 in normal mice and Prop1 mutants, and the results suggest Otx2 could influence pituitary development by affecting signaling from the ventral diencephalon and regulation of gene expression in Rathke's pouch. The discovery that Otx2 expression is affected by Prop1 deficiency provides support for our hypothesis that identifying molecular differences in mutants will contribute to understanding the molecular mechanisms that control pituitary organogenesis and lead to human pituitary disease.


2011 ◽  
Vol 85 (Suppl_1) ◽  
pp. 631-631 ◽  
Author(s):  
Siobhan W. Walsh ◽  
Jai P. Mehta ◽  
John A. Browne ◽  
Niamh Forde ◽  
Paul A. McGettigan ◽  
...  

2019 ◽  
Vol 26 (39) ◽  
pp. 6976-6990 ◽  
Author(s):  
Ana María González-Paramás ◽  
Begoña Ayuda-Durán ◽  
Sofía Martínez ◽  
Susana González-Manzano ◽  
Celestino Santos-Buelga

: Flavonoids are phenolic compounds widely distributed in the human diet. Their intake has been associated with a decreased risk of different diseases such as cancer, immune dysfunction or coronary heart disease. However, the knowledge about the mechanisms behind their in vivo activity is limited and still under discussion. For years, their bioactivity was associated with the direct antioxidant and radical scavenging properties of phenolic compounds, but nowadays this assumption is unlikely to explain their putative health effects, or at least to be the only explanation for them. New hypotheses about possible mechanisms have been postulated, including the influence of the interaction of polyphenols and gut microbiota and also the possibility that flavonoids or their metabolites could modify gene expression or act as potential modulators of intracellular signaling cascades. This paper reviews all these topics, from the classical view as antioxidants in the context of the Oxidative Stress theory to the most recent tendencies related with the modulation of redox signaling pathways, modification of gene expression or interactions with the intestinal microbiota. The use of C. elegans as a model organism for the study of the molecular mechanisms involved in biological activity of flavonoids is also discussed.


2020 ◽  
Vol 31 (4) ◽  
pp. 716-730 ◽  
Author(s):  
Marc Johnsen ◽  
Torsten Kubacki ◽  
Assa Yeroslaviz ◽  
Martin Richard Späth ◽  
Jannis Mörsdorf ◽  
...  

BackgroundAlthough AKI lacks effective therapeutic approaches, preventive strategies using preconditioning protocols, including caloric restriction and hypoxic preconditioning, have been shown to prevent injury in animal models. A better understanding of the molecular mechanisms that underlie the enhanced resistance to AKI conferred by such approaches is needed to facilitate clinical use. We hypothesized that these preconditioning strategies use similar pathways to augment cellular stress resistance.MethodsTo identify genes and pathways shared by caloric restriction and hypoxic preconditioning, we used RNA-sequencing transcriptome profiling to compare the transcriptional response with both modes of preconditioning in mice before and after renal ischemia-reperfusion injury.ResultsThe gene expression signatures induced by both preconditioning strategies involve distinct common genes and pathways that overlap significantly with the transcriptional changes observed after ischemia-reperfusion injury. These changes primarily affect oxidation-reduction processes and have a major effect on mitochondrial processes. We found that 16 of the genes differentially regulated by both modes of preconditioning were strongly correlated with clinical outcome; most of these genes had not previously been directly linked to AKI.ConclusionsThis comparative analysis of the gene expression signatures in preconditioning strategies shows overlapping patterns in caloric restriction and hypoxic preconditioning, pointing toward common molecular mechanisms. Our analysis identified a limited set of target genes not previously known to be associated with AKI; further study of their potential to provide the basis for novel preventive strategies is warranted. To allow for optimal interactive usability of the data by the kidney research community, we provide an online interface for user-defined interrogation of the gene expression datasets (http://shiny.cecad.uni-koeln.de:3838/IRaP/).


2021 ◽  
Vol 14 (1) ◽  
pp. 41
Author(s):  
Hana Votavova ◽  
Zuzana Urbanova ◽  
David Kundrat ◽  
Michaela Dostalova Merkerova ◽  
Martin Vostry ◽  
...  

Deferasirox (DFX) is an oral iron chelator used to reduce iron overload (IO) caused by frequent blood cell transfusions in anemic myelodysplastic syndrome (MDS) patients. To study the molecular mechanisms by which DFX improves outcome in MDS, we analyzed the global gene expression in untreated MDS patients and those who were given DFX treatment. The gene expression profiles of bone marrow CD34+ cells were assessed by whole-genome microarrays. Initially, differentially expressed genes (DEGs) were determined between patients with normal ferritin levels and those with IO to address the effect of excessive iron on cellular pathways. These DEGs were annotated to Gene Ontology terms associated with cell cycle, apoptosis, adaptive immune response and protein folding and were enriched in cancer-related pathways. The deregulation of multiple cancer pathways in iron-overloaded patients suggests that IO is a cofactor favoring the progression of MDS. The DEGs between patients with IO and those treated with DFX were involved predominantly in biological processes related to the immune response and inflammation. These data indicate DFX modulates the immune response mainly via neutrophil-related genes. Suppression of negative regulators of blood cell differentiation essential for cell maturation and upregulation of heme metabolism observed in DFX-treated patients may contribute to the hematopoietic improvement.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Karolina Stępniak ◽  
Magdalena A. Machnicka ◽  
Jakub Mieczkowski ◽  
Anna Macioszek ◽  
Bartosz Wojtaś ◽  
...  

AbstractChromatin structure and accessibility, and combinatorial binding of transcription factors to regulatory elements in genomic DNA control transcription. Genetic variations in genes encoding histones, epigenetics-related enzymes or modifiers affect chromatin structure/dynamics and result in alterations in gene expression contributing to cancer development or progression. Gliomas are brain tumors frequently associated with epigenetics-related gene deregulation. We perform whole-genome mapping of chromatin accessibility, histone modifications, DNA methylation patterns and transcriptome analysis simultaneously in multiple tumor samples to unravel epigenetic dysfunctions driving gliomagenesis. Based on the results of the integrative analysis of the acquired profiles, we create an atlas of active enhancers and promoters in benign and malignant gliomas. We explore these elements and intersect with Hi-C data to uncover molecular mechanisms instructing gene expression in gliomas.


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