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Liu J, Ning C, Zhang J, Xu S, Wu J, Tao C, Ma F, Chen Q, Pan Z. Comparative miRNA expression profile analysis of porcine ovarian follicles: new insights into the initiation mechanism of follicular atresia. Front Genet 2023; 14:1338411. [PMID: 38174044 PMCID: PMC10761487 DOI: 10.3389/fgene.2023.1338411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 12/06/2023] [Indexed: 01/05/2024] Open
Abstract
Follicular atresia occurs in every stage of ovarian development, which is relevant to female fertility. In the past decade, increasing studies have confirmed that miRNAs, a class of short non-coding RNAs, play an important role in follicular atresia by post-transcription regulation of their target genes. However, the function of miRNAs on follicular atresia initiation is unknown. In the present study, high-throughput small RNA sequencing was performed to analyze differential miRNA expression profiles between healthy (HF) follicles and early atretic (EAF) follicles. A total of 237 conserved miRNA were detected, and the miR-143 is the highest expressed in follicles. Meanwhile, we also found wide sequence variations (isomiRs) in porcine ovarian miRNA, including in 5'un-translation region, core seed sequences and 3'untranslation region. Furthermore, we identified 22 differentially expressed miRNAs in EAF groups compared to HF group, of which 3 miRNAs were upregulated, as well as 19 miRNAs were downregulated, and then the RT-PCR was performed to validate these profiles. The target genes of these differentially expressed miRNAs were predicted by using miRwalk, miRDB, and Targetscan database, respectively. Moreover, the gene ontology and KEGG pathway enrichment established that the regulating functions and signaling pathways of these miRNAs contribute to follicular atresia initiation and cell fate. In conclusion, this study provides new insights into the changes of miRNAs in early atretic follicles to demonstrate their molecular regulation in ovarian follicular atretic initiation.
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Affiliation(s)
- Jingge Liu
- College of Animal Science and Food Engineering, Jinling Institute of Technology, Nanjing, China
| | - Caibo Ning
- College of Animal Science and Technology, Nanjing Agriculture University, Nanjing, China
| | - Jinbi Zhang
- College of Animal Science and Food Engineering, Jinling Institute of Technology, Nanjing, China
| | - Shiyong Xu
- College of Animal Science and Food Engineering, Jinling Institute of Technology, Nanjing, China
| | - Jiege Wu
- College of Animal Science and Food Engineering, Jinling Institute of Technology, Nanjing, China
| | - Chenyu Tao
- College of Animal Science and Technology, Hebei Agricultural University, Baoding, China
| | - Fanhua Ma
- College of Animal Science and Food Engineering, Jinling Institute of Technology, Nanjing, China
| | - Qing Chen
- College of Animal Science and Food Engineering, Jinling Institute of Technology, Nanjing, China
| | - Zengxiang Pan
- College of Animal Science and Technology, Nanjing Agriculture University, Nanjing, China
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Roach CM, Bidne KL, Romoser MR, Ross JW, Baumgard LH, Keating AF. Impact of heat stress on prolactin-mediated ovarian JAK-STAT signaling in postpubertal gilts. J Anim Sci 2022; 100:6620801. [PMID: 35772766 PMCID: PMC9246670 DOI: 10.1093/jas/skac118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/08/2022] [Indexed: 12/20/2022] Open
Abstract
Heat stress (HS) compromises almost every aspect of animal agriculture including reproduction. In pigs, this infecundity is referred to as seasonal infertility (SI), a phenotype including ovarian dysfunction. In multiple species, HS-induced hyperprolactinemia has been described; hence, our study objectives were to characterize and compare HS effects on circulating prolactin (PRL) and ovarian Janus kinase/signal transducer and activator of transcription (JAK-STAT) signaling during the follicular (FOL) or luteal (LUT) phases of the estrous cycle in postpubertal gilts. Gilts were estrus synchronized using altrenogest and environmental treatments began immediately after altrenogest withdrawal. For the FOL study: postpubertal gilts were allocated to constant thermoneutral (TN; n = 6; 20 ± 1.2 °C) or cyclical HS (n = 6; 25 to 32 ± 1.2 °C) conditions for 5 d. In the LUT study: postpubertal gilts were assigned to either TN (n = 7; 20 ± 2.6 °C) or cyclical HS (n = 7; 32 to 35 ± 2.6 °C) conditions from 2 to 12 days postestrus (dpe). Blood was collected by jugular venipuncture for PRL quantification on day 5 in the FOL and on day 0 and day 12 in the LUT gilts. Ovaries and corpora lutea (CL) were obtained from euthanized FOL and LUT gilts on day 5 and day 12, respectively. Western blotting was performed to quantify prolactin receptor (PRLR) and JAK/STAT pathway protein abundance. In the FOL phase, no difference (P = 0.20) in circulating PRL between thermal groups was observed. There was no effect (P ≥ 0.34) of HS on PRLR, signal transducer and activator of transcription 3 (STAT3), signal transducer and activator of transcription 5α (STAT5α), and phosphorylated signal transducer and activator of transcription α/β tyrosine 694/699 (pSTAT5α/βTyr694/699) abundance and Janus kinase 2 (JAK2), phosphorylated janus kinase 2 tyrosine 1007/1008 (pJAK2Tyr1007/1008), STAT1, phosphorylated signal transducer and activator of transcription 1 tyrosine 701 (pSTAT1Tyr701), phosphorylated signal transducer and activator of transcription 1 serine 727 (pSTAT1Ser727), and phosphorylated signal transducer and activator of transcription 3 tyrosine 705 (pSTAT3Tyr705) were undetectable in FOL gilt ovaries. Ovarian pSTAT5α/βTyr694/699 abundance tended to moderately increase (4%; P = 0.07) in FOL gilts by HS. In the LUT phase, circulating PRL increased progressively from 2 to 12 dpe, but no thermal treatment-induced difference (P = 0.37) was noted. There was no effect (P ≥ 0.16) of HS on CL abundance of PRLR, pJAK2Tyr1007/1008, JAK2, STAT1, pSTAT1Tyr701, pSTAT1Ser727, pSTAT3Tyr705, STAT5α, or pSTAT5α/βTyr694/699. In LUT phase, CL STAT3 abundance was increased (11%; P < 0.03) by HS. There was no impact of HS (P ≥ 0.76) on levels of pJAK2Tyr1007/1008 and pSTAT5α/βTyr694/699 in LUT gilts; however, the CL pSTAT3Tyr705:STAT3 ratio tended to be decreased (P = 0.10) due to HS. These results indicate an HS-induced estrous cycle-stage-dependent effect on the ovarian JAK/STAT pathway, establishing a potential role for this signaling pathway as a potential contributor to SI.
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Affiliation(s)
- Crystal M Roach
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Katie L Bidne
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Matthew R Romoser
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Jason W Ross
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Lance H Baumgard
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Aileen F Keating
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
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Transcriptomics of cumulus cells - a window into oocyte maturation in humans. J Ovarian Res 2020; 13:93. [PMID: 32787963 PMCID: PMC7425158 DOI: 10.1186/s13048-020-00696-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/30/2020] [Indexed: 12/11/2022] Open
Abstract
Background Cumulus cells (CC) encapsulate growing oocytes and support their growth and development. Transcriptomic signatures of CC have the potential to serve as valuable non-invasive biomarkers for oocyte competency and potential. The present sibling cumulus-oocyte-complex (COC) cohort study aimed at defining functional variations between oocytes of different maturity exposed to the same stimulation conditions, by assessing the transcriptomic signatures of their corresponding CC. CC were collected from 18 patients with both germinal vesicle and metaphase II oocytes from the same cycle to keep the biological variability between samples to a minimum. RNA sequencing, differential expression, pathway analysis, and leading-edge were performed to highlight functional differences between CC encapsulating oocytes of different maturity. Results Transcriptomic signatures representing CC encapsulating oocytes of different maturity clustered separately on principal component analysis with 1818 genes differentially expressed. CCs encapsulating mature oocytes were more transcriptionally synchronized when compared with CCs encapsulating immature oocytes. Moreover, the transcriptional activity was lower, albeit not absent, in CC encapsulating mature oocytes, with 2407 fewer transcripts detected than in CC encapsulating immature (germinal vesicle - GV) oocytes. Hallmark pathways and ovarian processes that were affected by oocyte maturity included cell cycle regulation, steroid metabolism, apoptosis, extracellular matrix remodeling, and inflammation. Conclusions Herein we review our findings and discuss how they align with previous literature addressing transcriptomic signatures of oocyte maturation. Our findings support the available literature and enhance it with several genes and pathways, which have not been previously implicated in promoting human oocyte maturation. This study lays the ground for future functional studies that can enhance our understanding of human oocyte maturation.
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Qian H, Guan X. Follicle-stimulating hormone impairs dental pulp stem cells odontogenic differentiation. J Cell Mol Med 2020; 24:10621-10635. [PMID: 32725798 PMCID: PMC7521281 DOI: 10.1111/jcmm.15681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/06/2020] [Accepted: 07/09/2020] [Indexed: 12/24/2022] Open
Abstract
In addition to bone, the dentin‐pulp complex is also influenced by menopause, showing a decreased regenerative capacity. High levels of follicle‐stimulating hormone (FSH) during menopause could directly regulate bone metabolism. Here, the role of FSH in the odontogenic differentiation of the dentin‐pulp complex was investigated. Dental pulp stem cells (DPSCs) were isolated. CCK‐8 assays, cell apoptosis assays, Western blotting (WB), real‐time RT‐PCR, alkaline phosphatase activity assays, and Alizarin Red S staining were used to clarify the effects of FSH on the proliferation, apoptosis and odontogenic differentiation of the DPSCs. MAPK pathway‐related factors were explored by WB assays. FSH and its inhibitor were used in OVX rats combined with a direct pulp‐capping model. HE and immunohistochemistry were used to detect reparative dentin formation and related features. The results indicated that FSH significantly decreased the odontogenic differentiation of the DPSCs without affecting cell proliferation and apoptosis. Moreover, FSH significantly activated the JNK signalling pathway, and JNK inhibitor partly rescued the inhibitory effect of FSH on DPSC differentiation. In vivo, FSH treatment attenuated the dentin bridge formation and mineralization‐related protein expression in the OVX rats. Our findings indicated that FSH reduced the odontogenic capacity of the DPSCs and was involved in reparative dentinogenesis during menopause.
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Affiliation(s)
- Hua Qian
- Department of Tissue Engineering and Regeneration, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, Shandong, China
| | - Xiaoyue Guan
- Department of Endodontics, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
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Gogola J, Hoffmann M, Nimpsz S, Ptak A. Disruption of 17β-estradiol secretion by persistent organic pollutants present in human follicular fluid is dependent on the potential of ovarian granulosa tumor cell lines to metabolize estrogen. Mol Cell Endocrinol 2020; 503:110698. [PMID: 31891770 DOI: 10.1016/j.mce.2019.110698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/11/2019] [Accepted: 12/27/2019] [Indexed: 01/18/2023]
Abstract
Endocrine-disrupting chemicals (EDCs), such as perfluorooctanoate, perfluorooctane sulfonate, 2,2-dichlorodiphenyldichloroethylene, hexachlorobenzene, and polychlorinated biphenyl 153 are persistent pollutants that are found in human follicular fluid (FF). These compounds may affect endocrine function, disrupt steroid secretion by granulosa cells, and play a role in granulosa cell tumor (GCT) development. GCTs demonstrate endocrine activity, expressing aromatase and secreting 17β-estradiol (E2). We aimed to determine the effects of a mixture of EDCs, similar to that found in human FF, on human granulosa tumor cell lines representing the juvenile (JGCT) and adult (AGCT) forms (COV434 and KGN cells, respectively). We found that all the individual compounds and mixtures tested altered granulosa tumor cell function by disrupting E2 secretion. In KGN cells, which possess significantly higher basal aromatase gene expression, and therefore secrete more E2 than JGCT cells, EDC mixtures activated estrogen receptors (ERs) and G protein-coupled receptor-30 signaling, thereby stimulating E2 secretion, without affecting aromatase expression. By contrast, in COV434 cells, which demonstrate higher CYP1A1 expression, a key mediator of estrogen metabolism, than KGN cells, EDC mixtures reduced E2 secretion in parallel with increases in the 2-hydroxyestrogen 1/E2 ratio and CYP1A1 expression, implying an upregulation of E2 metabolism. These results indicate that the EDC mixture present in FF disrupts E2 secretion in JGCT and AGCT cells according to the estrogen metabolic potential of the cell type, involving both classical and non-classical ER pathways.
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Affiliation(s)
- Justyna Gogola
- Department of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland
| | - Marta Hoffmann
- Department of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland
| | - Samantha Nimpsz
- Department of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland
| | - Anna Ptak
- Department of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland.
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Chen N, Shan Q, Qi Y, Liu W, Tan X, Gu J. Transcriptome analysis in normal human liver cells exposed to 2, 3, 3', 4, 4', 5 - Hexachlorobiphenyl (PCB 156). CHEMOSPHERE 2020; 239:124747. [PMID: 31514003 DOI: 10.1016/j.chemosphere.2019.124747] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/31/2019] [Accepted: 09/03/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUNDS Polychlorinated biphenyls are persistent environmental pollutants associated with the onset of non-alcoholic fatty liver disease in humans, but there is limited information on the underlying mechanism. In the present study, we investigated the alterations in gene expression profiles in normal human liver cells L-02 following exposure to 2, 3, 3', 4, 4', 5 - hexachlorobiphenyl (PCB 156), a potent compound that may induce non-alcoholic fatty liver disease. METHODS The L-02 cells were exposed to PCB 156 for 72 h and the contents of intracellular triacylglyceride and total cholesterol were subsequently measured. Microarray analysis of mRNAs and long non-coding RNAs (lncRNAs) in the cells was also performed after 3.4 μM PCB 156 treatment. RESULTS Exposure to PCB 156 (3.4 μM, 72 h) resulted in significant increases of triacylglyceride and total cholesterol concentrations in L-02 cells. Microarray analysis identified 222 differentially expressed mRNAs and 628 differentially expressed lncRNAs. Gene Ontology and pathway analyses associated the differentially expressed mRNAs with metabolic and inflammatory processes. Moreover, lncRNA-mRNA co-expression network revealed 36 network pairs comprising 10 differentially expressed mRNAs and 34 dysregulated lncRNAs. The results of bioinformatics analysis further indicated that dysregulated lncRNA NONHSAT174696, lncRNA NONHSAT179219, and lncRNA NONHSAT161887, as the regulators of EDAR, CYP1B1, and ALDH3A1 respectively, played an important role in the PCB 156-induced lipid metabolism disorder. CONCLUSION Our findings provide an overview of differentially expressed mRNAs and lncRNAs in L-02 cells exposed to PCB 156, and contribute to the field of polychlorinated biphenyl-induced non-alcoholic fatty liver disease.
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Affiliation(s)
- Ningning Chen
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Qiuli Shan
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China; State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Yu Qi
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Wei Liu
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xiaojun Tan
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Jinsong Gu
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China
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Maillard V, Desmarchais A, Durcin M, Uzbekova S, Elis S. Docosahexaenoic acid (DHA) effects on proliferation and steroidogenesis of bovine granulosa cells. Reprod Biol Endocrinol 2018; 16:40. [PMID: 29699561 PMCID: PMC5918968 DOI: 10.1186/s12958-018-0357-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/18/2018] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Docosahexaenoic acid (DHA) is a n-3 polyunsaturated fatty acid (PUFA) belonging to a family of biologically active fatty acids (FA), which are known to have numerous health benefits. N-3 PUFAs affect reproduction in cattle, and notably directly affect follicular cells. In terms of reproduction in cattle, n-3 PUFA-enriched diets lead to increased follicle size or numbers. METHODS The objective of the present study was to analyze the effects of DHA (1, 10, 20 and 50 μM) on proliferation and steroidogenesis (parametric and/or non parametric (permutational) ANOVA) of bovine granulosa cells in vitro and mechanisms of action through protein expression (Kruskal-Wallis) and signaling pathways (non parametric ANOVA) and to investigate whether DHA could exert part of its action through the free fatty acid receptor 4 (FFAR4). RESULTS DHA (10 and 50 μM) increased granulosa cell proliferation and DHA 10 μM led to a corresponding increase in proliferating cell nuclear antigen (PCNA) expression level. DHA also increased progesterone secretion at 1, 20 and 50 μM, and estradiol secretion at 1, 10 and 20 μM. Consistent increases in protein levels were also reported for the steroidogenic enzymes, cytochrome P450 family 11 subfamily A member 1 (CYP11A1) and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 (HSD3B1), and of the cholesterol transporter steroidogenic acute regulatory protein (StAR), which are necessary for production of progesterone or androstenedione. FFAR4 was expressed in all cellular types of bovine ovarian follicles, and in granulosa cells it was localized close to the cellular membrane. TUG-891 treatment (1 and 50 μM), a FFAR4 agonist, increased granulosa cell proliferation and MAPK14 phosphorylation in a similar way to that observed with DHA treatment. However, TUG-891 treatment (1, 10 and 50 μM) showed no effect on progesterone or estradiol secretion. CONCLUSIONS These data show that DHA stimulated proliferation and steroidogenesis of bovine granulosa cells and led to MAPK14 phosphorylation. FFAR4 involvement in DHA effects requires further investigation, even if our data might suggest FFAR4 role in DHA effects on granulosa cell proliferation. Other mechanisms of DHA action should be investigated as the steroidogenic effects seemed to be independent of FFAR4 activation.
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Affiliation(s)
- Virginie Maillard
- 0000 0001 2182 6141grid.12366.30UMR PRC, CNRS, IFCE, INRA, Université de Tours, 37380 Nouzilly, France
- 0000 0004 0385 4036grid.464126.3INRA Centre Val de Loire, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Alice Desmarchais
- 0000 0001 2182 6141grid.12366.30UMR PRC, CNRS, IFCE, INRA, Université de Tours, 37380 Nouzilly, France
| | - Maeva Durcin
- 0000 0001 2182 6141grid.12366.30UMR PRC, CNRS, IFCE, INRA, Université de Tours, 37380 Nouzilly, France
| | - Svetlana Uzbekova
- 0000 0001 2182 6141grid.12366.30UMR PRC, CNRS, IFCE, INRA, Université de Tours, 37380 Nouzilly, France
| | - Sebastien Elis
- 0000 0001 2182 6141grid.12366.30UMR PRC, CNRS, IFCE, INRA, Université de Tours, 37380 Nouzilly, France
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Sirotkin AV, Benčo A, Tandlmajerová A, Lauková M, Vašíček D, Laurinčik J, Kornhauser J, Alwasel S, Harrath AH. cAMP response element-binding protein 1 controls porcine ovarian cell proliferation, apoptosis, and FSH and insulin-like growth factor 1 response. Reprod Fertil Dev 2018; 30:1145-1153. [DOI: 10.1071/rd17508] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 01/23/2018] [Indexed: 12/12/2022] Open
Abstract
The aim of the present study was to examine the role of cAMP response element-binding protein (CREB) and its phosphorylation in the regulation of ovarian cell proliferation and apoptosis, and of the response of proliferation and apoptosis to the upstream hormonal stimulators FSH and insulin-like growth factor (IGF) 1. In the first series of experiments, porcine ovarian granulosa cells, transfected or not with a gene construct encoding wild-type CREB1 (CREB1WT), were cultured with and without FSH (0, 1, 10 or 100 ng mL−1). In the second series of experiments, these cells were transfected or not with CREB1WT or non-phosphorylatable mutant CREB1 (CREB1M1) and cultured with and without FSH (0, 1, 10 or 100 ng mL−1) or IGF1 (0, 1, 10 and 100 ng mL−1). Levels of total and phosphorylated (p-) CREB1, proliferating cell nuclear antigen (PCNA), a marker of proliferation, and BAX, a marker of apoptosis, were evaluated by western immunoblotting and immunocytochemical analysis. Transfection of cells with CREB1WT promoted accumulation of total CREB1 within cells, but p-CREB1 was not detected in any cell group. Both CREB1WT and CREB1M1 reduced cell proliferation and apoptosis. Addition of 10 and 100 ng mL−1 FSH to non-transfected cells promoted CREB1 accumulation and apoptosis, whereas cell proliferation was promoted by all concentrations of FSH tested. FSH activity was not modified in cells transfected with either CREB1WT or CREB1M1. IGF1 at 100 ng mL−1 promoted cell proliferation, whereas all concentrations of IGF1 tested reduced apoptosis. Transfection with either CREB1WT or CREB1M1 did not modify the effects of either FSH or IGF1, although CREB1M1 reversed the effect of IGF1 on apoptosis from inhibitory to stimulatory. These observations suggest that CREB1 is involved in the downregulation of porcine ovarian cell proliferation and apoptosis. The absence of visible CREB1 phosphorylation and the similarity between the effects of CREB1WT and CREB1M1 transfection indicate that phosphorylation is not necessary for CREB1 action on these processes. Furthermore, the observations suggest that FSH promotes both ovarian cell proliferation and apoptosis, whereas IGF1 has proliferation-promoting and antiapoptotic properties. The effect of FSH on CREB1 accumulation and the ability of CREB1M1 to reverse the effects of IGF1 on apoptosis indicate that CREB1 is a mediator of hormonal activity, but the inability of either CREB1WT or CREBM1transfection to modify the primary effects of FSH and IGF1 suggest that CREB1 and its phosphorylation do not mediate the action of these hormones on ovarian cell proliferation and apoptosis.
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Abstract
To generate new hypotheses, sometimes a "systems" approach is needed. In this review, I focus on the mitogen-activated kinase p38 because it has been recently shown to play an important role in the developmental programing and senescence of normal and stressed reproductive tissues. What follows is an overview of (i) pathways of p38 activation and their involvement in basic biological processes, (ii) evidence that p38 is involved in the homeostasis of reproductive tissues, (iii) how focus on p38 can be incorporated into investigation of normal and stressed pregnancies. Existence of excellent reviews will be mentioned as well as relevant animal models.
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Affiliation(s)
- Elizabeth A Bonney
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Vermont, Burlington, VT, USA
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