skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells
Title: Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells
Phthalates are a class of known endocrine-disrupting chemicals that are found in common everyday products. Several studies associate phthalate exposure with detrimental effects on ovarian function, including growth and development of the follicle and production of steroid hormones. We hypothesized that dysregulation of the ovary by phthalates may be mediated by phthalate toxicity towards granulosa cells, a major cell type in ovarian follicles responsible for key steps of hormone production and nourishing the developing oocyte. To test the hypothesis that phthalates target granulosa cells, we harvested granulosa cells from adult CD-1 mouse ovaries and cultured them for 96 h in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1 to 100 μg/ml). After culture, we measured metabolism of the phthalate mixture into monoester metabolites by the granulosa cells, finding that granulosa cells do not significantly contribute to ovarian metabolism of phthalates. Immunohistochemistry of phthalate metabolizing enzymes in whole ovaries confirmed that these enzymes are not strongly expressed in granulosa cells of antral follicles and that ovarian metabolism of phthalates likely occurs primarily in the stroma. RNA sequencing of treated granulosa cells identified 407 differentially expressed genes, with overrepresentation of genes from lipid metabolic processes, cholesterol metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Expression of significantly differentially expressed genes related to these pathways was confirmed using qPCR. Our results agree with previous findings that phthalates and phthalate metabolites have different effects on the ovary, but both interfere with PPAR signaling in granulosa cells.  more » « less
Award ID(s):
2150363
PAR ID:
10599044
Author(s) / Creator(s):
; ; ; ; ; ; ;
Corporate Creator(s):
Editor(s):
Jeffrey, Peters; Alison, Harrill; Kristine, Willett
Publisher / Repository:
Society of Toxicology
Date Published:
Journal Name:
Current research in toxicology
Edition / Version:
final version
Volume:
202
Issue:
1
ISSN:
2666-027X
Page Range / eLocation ID:
69-84
Subject(s) / Keyword(s):
ovary phthalates granulosa cells peroxisome proliferator-activated receptor
Format(s):
Medium: X Size: 4mb Other: PDF/A
Size(s):
4mb
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; (, Reproductive toxicology)
    Di-2-ethylhexyl terephthalate (DEHTP) is a replacement for its structural isomer di-2-ethylhexyl phthalate (DEHP), a known endocrine disrupting chemical and ovarian toxicant. DEHTP is used as a plasticizer in polyvinyl chloride products and its metabolites are increasingly found in biomonitoring studies at levels similar to phthalates. However, little is known about the effects of DEHTP on the ovary. In this research, we tested the hypothesis that DEHTP is an ovarian toxicant and likely endocrine disrupting chemical like its isomer DEHP. The impact of environmentally relevant exposure to DEHTP and/or its metabolite mono-2-ethylhexyl terephthalate (MEHTP) on the mouse ovary was investigated in vivo and in vitro. For the in vivo studies, young adult CD-1 mice were orally dosed with vehicle, 10 µg/kg, 100 µg/kg, or 100 mg/kg of DEHTP for 10 days. For the in vitro studies, isolated untreated ovarian follicles were exposed to vehicle, 0.1, 1, 10, or 100 µg/mL of DEHTP or MEHTP. Follicle counts, hormone levels, and gene expression of steroidogenic enzymes, cell cycle regulators, and apoptosis factors were analyzed. In vivo, DEHTP exposure altered follicle counts compared to control. DEHTP exposure also decreased expression of cell cycle regulators and apoptotic factors compared to control. In vitro, follicle growth was reduced compared to controls, and expression of the cell cycle regulator Cdkn2b was increased. Overall, these results suggest that DEHTP and MEHTP may be ovarian toxicants at low doses and should be subjected to further scrutiny for reproductive toxicity due to their similar structures to phthalates. 
    more » « less
  2. ; ; ; ; ; ; ; (, Endocrinology)
    Abstract Mitochondria play important roles in ovarian follicle development. Mitochondrial dysfunction, including mitochondrial gene deficiency, impairs ovarian development. Here, we explored the role and mechanism of mitochondrial inner membrane gene Immp2l in ovarian follicle growth and development. Our results revealed that female Immp2l-/- mice were infertile, whereas Immp2l+/- mice were normal. Body and ovarian weights were reduced in the female Immp2l-/- mice, ovarian follicle growth and development were stunted in the secondary follicle stage. Although a few ovarian follicles were ovulated, the oocytes were not fertilized because of mitochondrial dysfunction. Increased oxidative stress, decreased estrogen levels, and altered genes expression of Wnt/β-catenin and steroid hormone synthesis pathways were observed in 28-day-old Immp2l-/- mice. The Immp2l mutation accelerated ovarian aging process, as no ovarian follicles were detected by age 5 months in Immp2l-/- mice. All the aforementioned changes in the Immp2l-/- mice were reversed by administration of antioxidant melatonin to the Immp2l-/- mice. Furthermore, our in vitro study using Immp2l knockdown granulosa cells confirmed that the Immp2l downregulation induced granulosa cell aging by enhancing reactive oxygen species (ROS) levels, suppressing Wnt16, increasing β-catenin, and decreasing steroid hormone synthesis gene cyp19a1 and estrogen levels, accompanied by an increase in the aging phenotype of granulosa cells. Melatonin treatment delayed granulosa cell aging progression. Taken together, Immp2l causes ovarian aging through the ROS-Wnt/β-catenin-estrogen (cyp19a1) pathway, which can be reversed by melatonin treatment. 
    more » « less
  3. ; ; (, PeerJ)
    Mechanism(s) that control whether individual human primordial ovarian follicles (PFs) remain dormant, or begin to grow, are all but unknown. One of our groups has recently shown that activation of the Integrated Stress Response (ISR) pathway can slow follicular granulosa cell proliferation by activating cell cycle checkpoints. Those data suggest that the ISR is active and fluctuates according to local conditions in dormant PFs. Because cell cycle entry of (pre)granulosa cells is required for PF growth activation (PFGA), we propose that rare ISR checkpoint resolution allows individual PFs to begin to grow. Fluctuating ISR activity within individual PFs can be described by a random process. In this article, we model ISR activity of individual PFs by one-dimensional random walks (RWs) and monitor the rate at which simulated checkpoint resolution and thus PFGA threshold crossing occurs. We show that the simultaneous recapitulation of (i) the loss of PFs over time within simulated subjects, and (ii) the timing of PF depletion in populations of simulated subjects equivalent to the distribution of the human age of natural menopause can be produced using this approach. In the RW model, the probability that individual PFs grow is influenced by regionally fluctuating conditions, that over time manifests in the known pattern of PFGA. Considered at the level of the ovary, randomness appears to be a key, purposeful feature of human ovarian aging. 
    more » « less
  4. ; ; ; ; ; ; ; ; (, Fertility and Sterility)
    OBJECTIVE: Rapamycin prolongs reproductive lifespan in mice by halting primordial follicle activation. The impact of rapamycin on the preantral follicle pool and senescence markers during ovarian aging in macaques was evaluated. MATERIALS AND METHODS: One ovary was removed from young (n=2, 6–9 yr) and old (n=2, 17–21 yr) adult female rhesus macaques during a normal menstrual cycle (pre-treatment). The remaining ovary was obtained after animals were treated with rapamycin (bid, IM, 0.02mg/kg) for 10 months. Ovaries were fixed and serially sectioned for follicle counting (each 10th section, 15-39 sections/ovary). Immunohistochemical analyses were performed for anti-Mullerian hormone (AMH) and cellular senescence markers p16, p53, and p21 (1 slide/ovary). Qualitative comparisons were made due to the small sample size. RESULTS: The primordial follicle pool was decreased in young (3,939 pre-treatment vs. 2,219 post-treatment), but similar in old (555 pre- vs. 574 post-treatment) females after rapamycin. The number of transitional primordial follicles was greater before rapamycin than after in both young (14,920 vs. 4,924) and old (1,915 vs. 1,311) females. The number of primary follicles before (2,617) rapamycin was greater than after (560) in young and old females (518 pre- vs. 428 post-treatment). A similar proportion of follicles positive for p16 was seen before and after rapamycin in both young and old females. Similar findings were also observed for AMH, except there are fewer positive follicles in the rapamycin-treated older group. The proportion of follicles staining positive for both p53 and p21 was increased in both young and old monkeys after treatment. CONCLUSIONS: Rapamycin had no impact on the primordial and primary follicle pools in old female macaques while unexpectedly decreasing both pools in young females. While the number of p16-positive follicles was unaffected by rapamycin treatment, the number of p53 and p21-positive follicles was increased by treatment in both age cohorts. IMPACT STATEMENT: At the dose and treatment interval used, rapamycin does not appear to suppress follicular activation and has mixed effects on senescence markers in aging nonhuman primate ovaries. 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Frontiers in Plant Science)
    Cultivated peanut ( Arachis hypogaea ) is one of the most widely grown food legumes in the world, being valued for its high protein and unsaturated oil contents. Drought stress is one of the major constraints that limit peanut production. This study’s objective was to identify the drought-responsive genes preferentially expressed under drought stress in different peanut genotypes. To accomplish this, four genotypes (drought tolerant: C76-16 and 587; drought susceptible: Tifrunner and 506) subjected to drought stress in a rainout shelter experiment were examined. Transcriptome sequencing analysis identified that all four genotypes shared a total of 2,457 differentially expressed genes (DEGs). A total of 139 enriched gene ontology terms consisting of 86 biological processes and 53 molecular functions, with defense response, reproductive process, and signaling pathways, were significantly enriched in the common DEGs. In addition, 3,576 DEGs were identified only in drought-tolerant lines in which a total of 74 gene ontology terms were identified, including 55 biological processes and 19 molecular functions, mainly related to protein modification process, pollination, and metabolic process. These terms were also found in shared genes in four genotypes, indicating that tolerant lines adjusted more related genes to respond to drought. Forty-three significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways were also identified, and the most enriched pathways were those processes involved in metabolic pathways, biosynthesis of secondary metabolites, plant circadian rhythm, phenylpropanoid biosynthesis, and starch and sucrose metabolism. This research expands our current understanding of the mechanisms that facilitate peanut drought tolerance and shed light on breeding advanced peanut lines to combat drought stress. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email