Fetal programming: in utero exposure to acrylamide leads to intergenerational disrupted ovarian function and accelerated ovarian aging

Toxicity mechanism of acrolein on energy metabolism disorder and apoptosis in human ovarian granulosa cells

Acrolein (ACR), an unsaturated, highly reactive aldehyde, is a widespread environmental toxin. ACR exerts permanent and irreversible side effects on ovarian functions. Granulosa cells play a crucial role in supporting ovarian function. Thus, in this study, we investigated the toxicity effects of granulosa cells induced by ACR. Following treatment with varying ACR concentrations (0, 12.5, 25, 50, and 100μM), we observed that ACR exposure induced reactive oxygen species accumulation, mitochondrial energy metabolism disorder, and apoptosis in KGN cells (a human ovarian granulosa cell line) in a dose-dependent manner. In addition, mitochondrial biogenesis in KGN cells displayed biphasic changes after ACR exposure, with activation at a low ACR dose (12.5μM), but inhibition at higher ACR doses (≥50μM). SIRT1/PGC-1α-mediated mitochondrial biogenesis is crucial for maintaining intracellular mitochondrial homeostasis and cellular function. The inhibition/activation of the SIRT1/PGC-1α pathway in KGN cells validated its role in ACR-induced damage. The results indicated that the inhibition of the SIRT1/PGC-1α pathway aggravated ACR-induced cell damage, whereas its activation partially counteracted ACR-induced cell damage. This study attempted to uncover a novel mechanism of ACR-induced ovarian toxicity so as to provide an effective treatment option for safeguarding female reproductive health from the adverse effects of ACR.

Early-Life Exposure to the Mycotoxin Fumonisin B1 and Developmental Programming of the Ovary of the Offspring: The Possible Role of Autophagy in Fertility Recovery

Mycotoxins are produced by more than one hundred fungi and produce secondary metabolites that contaminate various agricultural commodities, especially rice and corn. Their presence in the food chain is considered a serious problem worldwide. In recent years, a link between exposure to mycotoxins and impaired fertility has been suggested. Consequently, it has become vital to investigate the interactive effects of these mycotoxins on ovarian function. In this study, we investigated the intergenerational effects of the mycotoxin fumonisin B1 (FB1) on ovarian structure and function. Virgin Wistar albino female rats were separated into control and FB1 treatment groups and examined from day 6 of pregnancy until delivery (20 and 50 mg/kg b.w./day). The obtained female rats of the first (F1) and second generations (F2) were euthanized at 4 weeks of age, and ovary samples were collected. We found that the ovary weight index increased with the high dose of the treatment (50 mg/kg b.w./day) among both F1 and F2, in a manner similar to that observed in polycystic ovary syndrome. As expected, FB1 at a high dose (50 mg/kg b.w.) reduced the number of primordial follicles in F1 and F2, leading to an accelerated age-related decline in reproductive capacity. Moreover, it reduced the fertility rate among the F1 female rats by affecting follicle growth and development, as the number of secondary and tertiary follicles decreased. Histopathological changes were evidenced by the altered structures of most of the growing follicle oocytes, as revealed by a thinning irregular zona pellucida and pyknosis in granulosa cells. These findings are concomitant with steroidogenesis- and folliculogenesis-related gene expression, as evidenced by the decrease in CYP19 activity and estrogen receptor beta (ESR2) gene expression. Additionally, GDF-9 mRNA levels were significantly decreased, and IGF-1 mRNA levels were significantly increased. However, the results from the ovaries of the F2 treatment groups were different and unexpected. While there was no significant variation in CYP19 activity compared to the control, the ESR2 significantly increased, leading to stereological and histopathological changes similar to those of the control, except for some altered follicles. The hallmark histological feature was the appearance of vacuolar structures within the oocyte and between granulosa cell layers. Interestingly, the autophagic marker LC3 was significantly increased in the F2 offspring, whereas this protein was significantly decreased in the F1 offspring. Therefore, we suggest that the promotion of autophagy in the ovaries of the F2 offspring may be considered a recovery mechanism from the effect of prenatal FB1 exposure. Thus, autophagy corrected the effect of FB1 during the early life of the F1 female rats, leading to F2 offspring with ovarian structure and function similar to those of the control. However, the offspring, treated female rats may experience early ovarian aging because their ovarian pool was affected.

Detection and Quantification of Acrylamide in Second Trimester Amniotic Fluid Using a Novel LC-MS/MS Technique to Determine Whether High Acrylamide Content during Pregnancy Is Associated with Fetal Growth

INTRODUCTION

Acrylamide, an organic compound, is, chemically speaking, a vinyl-substituted primary amide. It is produced industrially, principally as a precursor to polyacrylamides, for use in such products as plastics and cosmetics. This same compound, however, forms naturally in certain foods, both home-cooked and packaged, especially when prepared at high temperatures. We developed and validated a novel reliable technique for the determination of acrylamide in amniotic fluid. Multiple reaction monitoring (MRM) is a targeted mass spectrometry (MS) technique which enables the detection and quantification of particular molecules in a complex mixture. Thanks to its throughput, selectivity, and sensitivity, MRM-MS has been identified as offering an alternative to antibody-based studies for the purpose of biomarker verification. Our aim was to investigate the presence of acrylamide in amniotic fluid and, via the MRM-MS technique, to determine whether there is any correlation between maternal exposure to acrylamide, through a woman's diet, and fetal growth.

METHODS

Our amniotic fluid bank included 40 samples from various fetal growth rates, as objectively denoted by the neonatal weight centile at delivery, while our analytical detection method was based on liquid chromatography-tandem mass spectrometry (LC-MS/MS). Acrylamide was determined with reversed phase chromatography and monitoring of two multiple reaction monitoring (MRM) transitions. Quantification was performed using the matrix-matched calibration curve.

RESULTS

Acrylamide was detected at concentrations between 7.1 and 1468 ng/mL in six out of the total of 40 amniotic fluid samples that were used. Our method limit of detection and quantification was 1.4 ng/mL and 4.6 ng/mL, respectively. The repeatability of our method ranged between 11 and 14%, expressed as relative standard deviation levels between 5 and 100 ng/mL.

CONCLUSIONS

Detection of acrylamide in early second trimester amniotic fluid, for the first time in the literature to our knowledge, raises concerns about fetal health, given that published data on animal studies have attributed a number of birth defects to acrylamide. Our novel LC-MS/MS method for the determination of acrylamide in amniotic fluid proved to be effective and its performance in practice was very accurate, simple, and fast. Validation of the method revealed that the use of a matrix-matched curve is necessary for the quantification.