scholarly journals Investigation of exposure to lifestyle and environmental factors on cumulus-oocyte complex function

2021 ◽  
Author(s):  
◽  
Kelly Anne Campen

<p>Pathways involved in bi-directional communication within the cumulus-oocyte complex (COC) include gap junction (GJ) communication, oocyte growth factor production, and glucose metabolism and are essential for oocyte health. Perturbation of these pathways may result in reduced oocyte quality due to altered COC function. Using rats as a model, in vitro effects of exposure to bisphenol A (BPA), caffeine, nicotine, ethanol, methylenedioxymeth- amphetamine (MDMA), or Δ⁹-tetrahydrocannabinol (THC) on COC function were investigated. Furthermore, MDMA was administered to rats to compare in vitro with in vivo effects.  The transfer of a fluorescent dye (calcein) from cumulus cells (CC) to the oocyte was used as a measure of GJ communication. Expression of CC-derived (Atr, Cx43, Cycs, Gfpt1, Pfkp) and oocyte-derived (Atr, Bmp15, Cx37, Gdf9) genes were measured using multiplex TaqMan quantitative PCR. Levels of CX43 and GDF9 proteins were quantified using Western blotting.  Optimisation of the GJ bioassay included the addition of phosphodiesterase inhibitors (rolipram and dipyridamole), and a 1 hour post-calcein incubation period to allow dye transfer. Quantification of gene expression in calcein-treated CC and oocytes was validated, enabling direct comparisons between GJ communication and gene expression.  To determine the in vitro effects, COC were incubated with test factors at high physiological concentrations over 25 hours. GJ communication decreased over time in control COC. This reduction was attenuated after exposure to BPA and nicotine, and partially by caffeine. Furthermore, exposure to ethanol maintained oocyte meiotic arrest, whereas MDMA and THC promoted meiotic resumption.  Oocyte-derived gene expression was mostly unaffected by in vitro exposure to the lifestyle and environmental factors, although a treatment x time interaction for Cx37 levels following nicotine exposure was observed. Of the CC-derived genes, Cx43 was the most sensitive where BPA, MDMA, and THC increased, and caffeine and ethanol decreased, expression. In CC, exposure to MDMA and THC increased Gfpt1 levels and exposure to MDMA resulted in a treatment x time interaction in Cycs and Pfkp expression.  In COC, caffeine increased CX43 protein levels after 1 hour. Nicotine initially reduced, but with time increased CX43 levels. Furthermore, CX43 levels decreased and increased after 25 hour exposures to ethanol and MDMA, respectively. GDF9 protein levels in COC exhibited wide within-treatment variation. Overall, BPA and caffeine reduced GDF9 levels after 1 hour whereas GDF9 levels were increased following exposure to BPA, caffeine, MDMA, and THC for 25 hours.  To determine in vivo effects, female rats were administered saline or 5 mg/kg/day MDMA for 3 days. COC from MDMA-treated rats had higher levels of CX43 protein but gene expression and meiotic reactivation were unaffected.  In conclusion, COC function was altered by in vitro exposure to BPA, caffeine, ethanol, nicotine, MDMA, and THC. Furthermore, in vivo exposure to MDMA elicits similar, albeit reduced, effects on COC function. A role for CC in protecting the oocyte from harmful contaminants is proposed. Perturbation of the bi-directional communication pathway is likely to influence oocyte quality due to alterations in nutrient availability and timing of follicular events, although these may not be associated with negative outcomes. This study provides evidence that exposure to lifestyle factors and environmental contaminants affect COC function.</p>

2021 ◽  
Author(s):  
◽  
Kelly Anne Campen

<p>Pathways involved in bi-directional communication within the cumulus-oocyte complex (COC) include gap junction (GJ) communication, oocyte growth factor production, and glucose metabolism and are essential for oocyte health. Perturbation of these pathways may result in reduced oocyte quality due to altered COC function. Using rats as a model, in vitro effects of exposure to bisphenol A (BPA), caffeine, nicotine, ethanol, methylenedioxymeth- amphetamine (MDMA), or Δ⁹-tetrahydrocannabinol (THC) on COC function were investigated. Furthermore, MDMA was administered to rats to compare in vitro with in vivo effects.  The transfer of a fluorescent dye (calcein) from cumulus cells (CC) to the oocyte was used as a measure of GJ communication. Expression of CC-derived (Atr, Cx43, Cycs, Gfpt1, Pfkp) and oocyte-derived (Atr, Bmp15, Cx37, Gdf9) genes were measured using multiplex TaqMan quantitative PCR. Levels of CX43 and GDF9 proteins were quantified using Western blotting.  Optimisation of the GJ bioassay included the addition of phosphodiesterase inhibitors (rolipram and dipyridamole), and a 1 hour post-calcein incubation period to allow dye transfer. Quantification of gene expression in calcein-treated CC and oocytes was validated, enabling direct comparisons between GJ communication and gene expression.  To determine the in vitro effects, COC were incubated with test factors at high physiological concentrations over 25 hours. GJ communication decreased over time in control COC. This reduction was attenuated after exposure to BPA and nicotine, and partially by caffeine. Furthermore, exposure to ethanol maintained oocyte meiotic arrest, whereas MDMA and THC promoted meiotic resumption.  Oocyte-derived gene expression was mostly unaffected by in vitro exposure to the lifestyle and environmental factors, although a treatment x time interaction for Cx37 levels following nicotine exposure was observed. Of the CC-derived genes, Cx43 was the most sensitive where BPA, MDMA, and THC increased, and caffeine and ethanol decreased, expression. In CC, exposure to MDMA and THC increased Gfpt1 levels and exposure to MDMA resulted in a treatment x time interaction in Cycs and Pfkp expression.  In COC, caffeine increased CX43 protein levels after 1 hour. Nicotine initially reduced, but with time increased CX43 levels. Furthermore, CX43 levels decreased and increased after 25 hour exposures to ethanol and MDMA, respectively. GDF9 protein levels in COC exhibited wide within-treatment variation. Overall, BPA and caffeine reduced GDF9 levels after 1 hour whereas GDF9 levels were increased following exposure to BPA, caffeine, MDMA, and THC for 25 hours.  To determine in vivo effects, female rats were administered saline or 5 mg/kg/day MDMA for 3 days. COC from MDMA-treated rats had higher levels of CX43 protein but gene expression and meiotic reactivation were unaffected.  In conclusion, COC function was altered by in vitro exposure to BPA, caffeine, ethanol, nicotine, MDMA, and THC. Furthermore, in vivo exposure to MDMA elicits similar, albeit reduced, effects on COC function. A role for CC in protecting the oocyte from harmful contaminants is proposed. Perturbation of the bi-directional communication pathway is likely to influence oocyte quality due to alterations in nutrient availability and timing of follicular events, although these may not be associated with negative outcomes. This study provides evidence that exposure to lifestyle factors and environmental contaminants affect COC function.</p>


2010 ◽  
Vol 22 (1) ◽  
pp. 285
Author(s):  
T. T. B. Vo ◽  
E. B. Jeung

In the current study, calbindin-D9k (CaBP-9k), a potent biomarker for screening estrogen-like environmental chemicals in vivo and in vitro, was adopted to examine the potential estrogen-like property of the following parabens: propyl-, isopropyl-, butyl-, and isobutyl-paraben. Immature female rats were administered for 3 days from postnatal day 14 to 16 with 17?-ethinylestradiol (EE, 1 mg/kg of body weight (BW) per day) or parabens (62.5, 250, and 1000 mg/kg of BW per day). In uterotrophic assays, significantly increased uterus weights were detected in the EE-treated group and in the groups treated with the greatest dose of isopropyl-, butyl- and isobutyl-paraben. In addition, these parabens induced uterine CaBP-9k mRNA and protein levels, whereas co-treatment of parabens and fulvestrant (Faslodex, formerly known as ICI 182, 780), a pure estrogen receptor (ER) antagonist, completely reversed the paraben-induced gene expression and increased uterine weights. To investigate the ER-mediated mechanism(s) by which parabens exert their effects, the expression level of ERα and progesterone receptor (PR) was analyzed. Exposure to EE or parabens caused a dramatic decrease in expression of both ER? mRNA and protein levels, whereas co-treatment with fulvestrant reversed these effects. These data showed the difference of CaBP-9k and ER? expression, suggesting that CaBP-9k might not express via ER? pathway. In the effect of parabens on CaBP-9k expression through PR mediation, a significantly increased expression of uterine PR gene, a well-known ER regulating gene, at both transcriptional and translational levels was indicated in the greatest dose of isopropyl- and butyl-paraben. These parabens induced PR gene expression that was completely blocked by fulvestrant. This result indicates that CaBP-9k expression might involve PR mediates in the estrogenic effect of paraben in immature rat uteri. Taken together, parabens exhibited an estrogen-like property in vivo, which might be mediated by a PR and/or ER? signaling pathway. In addition, our results expanded the current understanding of the potential adverse effects of parabens associated with their estrogen-like activities. Further investigation is needed to elucidate in greater detail the adverse effects of parabens in humans and wildlife.


Zygote ◽  
2019 ◽  
Vol 27 (05) ◽  
pp. 321-328
Author(s):  
Lucas Teixeira Hax ◽  
Joao Alveiro Alvarado Rincón ◽  
Augusto Schneider ◽  
Lígia Margareth Cantarelli Pegoraro ◽  
Letícia Franco Collares ◽  
...  

SummaryAround 60–80% of oocytes maturated in vivo reached competence, while the proportion of maturation in vitro is rarely higher than 40%. In this sense, butafosfan has been used in vivo to improve metabolic condition of postpartum cows, and can represent an alternative to increase reproductive efficiency in cows. The aim of this study was to evaluate the addition of increasing doses of butafosfan during oocyte maturation in vitro on the initial embryo development in cattle. In total, 1400 cumulus–oocyte complexes (COCs) were distributed in four groups and maturated according to supplementation with increasing concentrations of butafosfan (0 mg/ml, 0.05 mg/ml, 0.1 mg/ml and 0.2 mg/ml). Then, 20 oocytes per group were collected to evaluate nuclear maturation and gene expression on cumulus cells and oocytes and the remaining oocytes were inseminated and cultured until day 7, when blastocysts were collected for gene expression analysis. A dose-dependent effect of butafosfan was observed, with decrease of cleavage rate and embryo development with higher doses. No difference between groups was observed in maturation rate and expression of genes related to oocyte quality. Our results suggest that butafosfan is prejudicial for oocytes, compromising cleavage and embryo development.


1983 ◽  
Vol 6 (9) ◽  
pp. 643-653 ◽  
Author(s):  
TAKAAKI AOYAGI ◽  
TAKAO WADA ◽  
KAZUO UMEZAWA ◽  
FUKIKO KOJIMA ◽  
MACHIKO NAGAI ◽  
...  

2009 ◽  
Vol 296 (6) ◽  
pp. C1321-C1328 ◽  
Author(s):  
R. P. Rhoads ◽  
R. M. Johnson ◽  
C. R. Rathbone ◽  
X. Liu ◽  
C. Temm-Grove ◽  
...  

Muscle regeneration involves the coordination of myogenesis and revascularization to restore proper muscle function. Myogenesis is driven by resident stem cells termed satellite cells (SC), whereas angiogenesis arises from endothelial cells and perivascular cells of preexisting vascular segments and the collateral vasculature. Communication between myogenic and angiogenic cells seems plausible, especially given the number of growth factors produced by SC. To characterize these interactions, we developed an in vitro coculture model composed of rat skeletal muscle SC and microvascular fragments (MVF). In this system, isolated epididymal MVF suspended in collagen gel are cultured over a rat SC monolayer culture. In the presence of SC, MVF exhibit greater indices of angiogenesis than MVF cultured alone. A positive dose-dependent effect of SC conditioned medium (CM) on MVF growth was observed, suggesting that SC secrete soluble-acting growth factor(s). Next, we specifically blocked VEGF action in SC CM, and this was sufficient to abolish satellite cell-induced angiogenesis. Finally, hypoxia-inducible factor-1α (HIF-1α), a transcriptional regulator of VEGF gene expression, was found to be expressed in cultured SC and in putative SC in sections of in vivo stretch-injured rat muscle. Hypoxic culture conditions increased SC HIF-1α activity, which was positively associated with SC VEGF gene expression and protein levels. Collectively, these initial observations suggest that a heretofore unexplored aspect of satellite cell physiology is the initiation of a proangiogenic program.


2017 ◽  
Vol 126 (04) ◽  
pp. 255-262 ◽  
Author(s):  
Katarína Chalásová ◽  
Lukáš Pácal ◽  
Anna Pleskačová ◽  
Lucia Knopfová ◽  
Jitka Řehořová ◽  
...  

Abstract Aim Pentose phosphate pathway (PPP) with key enzyme transketolase (TKT), represents a potentially ‘protective’ mechanism in hyperglycaemia. Diabetic kidney disease (DKD), a common complication of both type 1 and type 2 diabetes associated with significant morbidity and mortality, represents the most common cause of chronic kidney disease (CKD). We hypothesized that protective PPP action in diabetes and eventually even more severely in concomitant DKD might be compromised by limited intracellular availability of an active TKT cofactor thiamine diphosphate (TDP). Methods Effect of hyperglycaemia on gene expression and protein levels of key PPP loci was studied in vitro using human cell lines relevant to diabetes (HUVEC and HRGEC) and (together with measurement of TKT activity, plasma thiamine and erythrocyte TDP concentration) in vivo in diabetic vs. non-diabetic subjects with comparable renal function (n=83 in total). Results Hyperglycaemia significantly decreased protein levels of RFC-1, THTR1, THTR2 and TKT (P<0.05) in vitro. Analysis of blood samples from CKD patients with and without diabetes and from controls did not reveal any difference in gene expression and protein levels of thiamine transporters while TKT activity and TDP in erythrocytes gradually increased with decreasing kidney function being highest in patients with CKD3-4 of both diabetic and non-diabetic aetiology. Hyperglycaemia and uremic serum mimicking CKD in diabetes did not affect TKT activity in vitro (P<0.05). Conclusion Both in vitro and human experiments showed decrease or unchanged expression, respectively, of thiamine transporters induced by hyperglycaemia while TKT activity in parallel with intracellular TDP was increased in CKD patients with or without diabetes. Therefore, lack of adaptive increase of thiamine transmembrane transport allowing further increase of TKT activity might contribute to compromised PPP function in diabetes and CKD and to the development of glycotoxic injury.


Sign in / Sign up

Export Citation Format

Share Document