Melatonin supplementation in the culture medium rescues impaired glucose metabolism in IVF mice offspring

TET1 overexpression affects cell proliferation and apoptosis in aging ovaries

PURPOSE

Along with the progress of society, human life expectancy has been increasing, and late marriage and late childbearing are the current trend. Since reproductive aging affects fertility, ovarian aging in women has become a major reproductive health issue in the current society. During ovarian aging, DNA methylation levels may change. The ten-eleven translocation (TET) protein family proteins TET1, TET2, and TET3 are important DNA demethylation enzymes, and differential expression of TET1, TET2, and TET3 may affect the proliferation and apoptosis of aging ovarian cells. The aim of this study was to investigate the role of TET1 in the regulation of ovarian aging.

METHODS

The expression of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) was analyzed by immunofluorescence (IF) in young and aging ovaries of six 6-8-week-old female mice and six 6-8-month-old female mice. Then, the expression pattern of the TET protein family in young and aging ovaries of mice was investigated. To determine the impact of TET1 on ovarian development, the aging of IOSE-80, KGN, and SKOV-3 cells was induced with D-galactosidase (D-gal). Cells were then transfected using the TET1 overexpression vector or si-TET1. We assessed the proliferation and apoptosis of aging cells after transfection and analyzed the regulatory effect of TET1 expression on aging cells. Additionally, we verified the Tet1 expression in Tet1-KO mice.

RESULTS

The 5mC to 5hmC transition, oocyte maturation, and blastocyst rate were reduced in aging mice compared to young mice. In aging mice ovaries, the expression levels of Tet1, Tet2, and Tet3 were reduced significantly, with Tet1 being particularly pronounced. The overexpression of TET1 promoted proliferation and inhibited apoptosis in aging human ovarian cells. Furthermore, Tet1 expression was very low in Tet1-KO C57BL/6 J mice ovaries.

CONCLUSION

This study demonstrates that the expression levels of TET family proteins are low in aging ovaries, and the overexpression of TET1 can promote proliferation and inhibit apoptosis in aging ovarian cells.

Sperm miR-142-3p Reprogramming Mediates Paternal Pre-Pregnancy Caffeine Exposure-Induced Non-Alcoholic Steatohepatitis in Male Offspring Rats

Numerous studies have suggested a strong association between paternal adverse environmental exposure and increased disease susceptibility in offspring. However, the impact of paternal pre-pregnant caffeine exposure (PPCE) on offspring health remains unexplored. This study elucidates the sperm reprogramming mechanism and potential intervention targets for PPCE-induced non-alcoholic steatohepatitis (NASH) in offspring. Here, male rats are administrated caffeine (15-60 mg kg-1/d) by gavage for 8 weeks and then mated with females to produce offspring. This study finds that NASH with transgenerational inheritance occurred in PPCE adult offspring. Mechanistically, a reduction of miR-142-3p is implicated in the occurrence of NASH, characterized by hepatic lipid metabolism dysfunction and chronic inflammation through an increase in ACSL4. Conversely, overexpression of miR-142-3p mitigated these manifestations. The origin of reduced miR-142-3p levels is traced to hypermethylation in the miR-142-3p promoter region of parental sperm, induced by elevated corticosterone levels rather than by caffeine per se. Similar outcomes are confirmed in offspring conceived via in vitro fertilization using miR-142-3pKO sperm. Overall, this study provides the first evidence of transgenerational inheritance of NASH in PPCE offspring and identifies miR-142-3p as a potential therapeutic target for NASH induced by paternal environmental adversities.

IVF exposure induced intergenerational effects on metabolic phenotype in mice

RESEARCH QUESTION

What is the potential transmission of metabolic phenotype from IVF offspring to the subsequent generation?

DESIGN

An IVF mouse model was established. The F1 generation mice were produced though IVF or natural mating and the F2 generation was obtained through the mating of F1 generation males with normal females. Their metabolic phenotype, including systemic and hepatic glucolipid metabolism, was examined.

RESULTS

It was found that IVF F1 males exhibited metabolic changes. Compared with the control group, the IVF F1 generation showed increased body weight, elevated fasting glucose and insulin, and increased serum triglyceride concentrations. IVF F1 mice also showed an increased expression of hepatic lipogenesis and autophagy genes. Moreover, IVF F1 males transmitted some metabolic changes to their own male progeny (IVF F2) in the absence of a dietary challenge. IVF F2 mice had increased peri-epididymal and subcutaneous fat and decreased insulin sensitivity. Under the 'second hit' of a high-fat diet, IVF F2 mice further showed increased hepatic lipid deposition with unaltered autophagy levels.

CONCLUSION

This research demonstrates the impact of IVF on hepatic glucose-lipid metabolism in two successive generations of offspring, highlighting the need for additional investigation. Enhanced understanding of the mechanisms underlying the transmission of multigenerational effects induced by IVF could potentially lead to the advancement of therapeutic interventions for individuals experiencing infertility.

Dissecting microenvironment in cystadenomas and hepatic cysts based on single nucleus RNA-sequencing data

Hepatic cystadenoma is a rare disease, accounting for about 5% of all cystic lesions, with a high tendency of malignant transformation. The preoperative diagnosis of cystadenoma is difficult, and some cystadenomas are easily misdiagnosed as hepatic cysts at first. Hepatic cyst is a relatively common liver disease, most of which are benign, but large hepatic cysts can lead to pressure on the bile duct, resulting in abnormal liver function. To better understand the difference between the microenvironment of cystadenomas and hepatic cysts, we performed single-nuclei RNA-sequencing on cystadenoma and hepatic cysts samples. In addition, we performed spatial transcriptome sequencing of hepatic cysts. Based on nucleus RNA-sequencing data, a total of seven major cell types were identified. Here we described the tumor microenvironment of cystadenomas and hepatic cysts, particularly the transcriptome signatures and regulators of immune cells and stromal cells. By inferring copy number variation, it was found that the malignant degree of hepatic stellate cells in cystadenoma was higher. Pseudotime trajectory analysis demonstrated dynamic transformation of hepatocytes in hepatic cysts and cystadenomas. Cystadenomas had higher immune infiltration than hepatic cysts, and T cells had a more complex regulatory mechanism in cystadenomas than hepatic cysts. Immunohistochemistry confirms a cystadenoma-specific T-cell immunoregulatory mechanism. These results provided a single-cell atlas of cystadenomas and hepatic cyst, revealed a more complex microenvironment in cystadenomas than in hepatic cysts, and provided new perspective for the molecular mechanisms of cystadenomas and hepatic cyst.

Long-term health risk of offspring born from assisted reproductive technologies

Since the world's first in vitro fertilization baby was born in 1978, there have been more than 8 million children conceived through assisted reproductive technologies (ART) worldwide, and a significant proportion of them have reached puberty or young adulthood. Many studies have found that ART increases the risk of adverse perinatal outcomes, including preterm birth, low birth weight, small size for gestational age, perinatal mortality, and congenital anomalies. However, data regarding the long-term outcomes of ART offspring are limited. According to the developmental origins of health and disease theory, adverse environments during early life stages may induce adaptive changes and subsequently result in an increased risk of diseases in later life. Increasing evidence also suggests that ART offspring are predisposed to an increased risk of non-communicable diseases, such as malignancies, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders. In this review, we summarize the risks for long-term health in ART offspring, discuss the underlying mechanisms, including underlying parental infertility, epigenetic alterations, non-physiological hormone levels, and placental dysfunction, and propose potential strategies to optimize the management of ART and health care of parents and children to eliminate the associated risks. Further ongoing follow-up and research are warranted to determine the effects of ART on the long-term health of ART offspring in later life.

Melatonin inhibits the formation of intraplaque neovessels in ApoE-/- mice via PPARγ- RhoA-ROCK pathway

BACKGROUND

According to former research, the atherosclerotic plaque is thought to be aggravated by intraplaque neovessels (IPN) and intraplaque hemorrhage (IPH). Intriguingly, a lower incidence of IPH was found in plaque treated with melatonin. In this study, we attempted to investigate the impact and underlying mechanism regarding the influences of melatonin upon IPN.

METHODS

A mouse model was established by subjecting the high fat diet (HFD)-fed ApoE-/- mice to tandem stenosis (TS) surgery with melatonin and GW9662, a PPARγ antagonist, being given by gavage. In vitro experiment was conducted with HUVECs exposing to according treatments of VEGF, melatonin, GW9662, or Y27632.

RESULTS

Plaque and IPN were attenuated by treatment with melatonin, which was then reversed by blocking PPARγ. Western blotting results showed that melatonin increased PPARγ and decreased RhoA/ROCK signaling in carotid artery. Elevated RhoA/ROCK signaling was observed in melatonin-treated mice when PPARγ was blocked. In accordance with it, experiments using protein and mRNA from HUVECs revealed that melatonin inhibited the RhoA/ROCK signaling by enhancing PPARγ. According to in vitro study, melatonin was able to inhibit cell migration and angiogenesis, which was aborted by GW9662. Blockage of ROCK using Y27632 was able to cease the effect of GW9662 and restored the suppression on cell migration and angiogenesis by melatonin.

CONCLUSIONS

Our study demonstrates that melatonin is able to curb development of plaque and IPN formation by inhibiting the migration of endothelial cells via PPARγ- RhoA-ROCK pathway. That provides a therapeutic potential for both melatonin and PPARγ agonist targeting IPN, IPH, and atherosclerotic plaque.

NRF2 attenuation aggravates detrimental consequences of metabolic stress on cultured porcine parthenote embryos

The nuclear factor erythroid 2-related factor 2 (NRF2) is a crucial transcription factor that plays a central role in regulating oxidative stress pathways by binding antioxidant response elements, but its involvement in early embryo development remains largely unexplored. In this study, we demonstrated that NRF2 mRNA is expressed in porcine embryos from day 2 to day 7 of development, showing a decrease in abundance from day 2 to day 3, followed by an increase on day 5 and day 7. Comparable levels of NRF2 mRNA were observed between early-cleaving and more developmental competent embryos and late-cleaving and less developmental competent embryos on day 4 and day 5 of culture. Attenuation of NRF2 mRNA significantly decreased development of parthenote embryos to the blastocyst stage. When NRF2-attenuated embryos were cultured in presence of 3.5 mM or 7 mM glucose, development to the blastocyst stage was dramatically decreased in comparison to the control group (15.9% vs. 27.8% for 3.5 mM glucose, and 5.4% vs. 25.3% for 7 mM glucose). Supplementation of melatonin moderately improved the development of NRF2-attenuated embryos cultured in presence of 0.6 mM glucose. These findings highlight the importance of NRF2 in early embryo development, particularly in embryos cultured under metabolically stressful conditions.

The Impact of Follicular Fluid Oxidative Stress Levels on the Outcomes of Assisted Reproductive Therapy

Oocyte quality is a pivotal determinant of assisted reproductive outcomes. The quality of oocytes is intricately linked to their developmental microenvironment, particularly the levels of oxidative stress within the follicular fluid. Oxidative stress levels in follicular fluid may have a substantial influence on oocyte health, thereby impacting the outcomes of ART procedures. This review meticulously explores the intricate relationship between oxidative stress in follicular fluid and ART outcomes. Furthermore, it delves into strategies aimed at ameliorating the oxidative stress status of follicular fluid, with the overarching goal of enhancing the overall efficacy of ART. This research endeavors to establish a robust foundation and provide valuable guidance for clinical treatment approaches, particularly in the context of infertile women, including those of advanced maternal age.

Assessment of developmental rate of mouse embryos yielded from in vitro fertilization of the oocyte with treatment of melatonin and vitamin C simultaneously

BACKGROUND

In recent decades, in vitro fertilization (IVF) has been widely used as a method of assisted reproductive technology (ART) to improve fertility in individuals. To be more successful in this laboratory method, we used the presence of two common types of antioxidants (melatonin and vitamin C) simultaneously and exclusively in IVF medium.

METHODS

The cumulus-oocyte complexes (COCs) were obtained from Gonadotropin-releasing hormone (GnRH) and Human Chorionic Gonadotropin (HMG) -stimulated mice. Subsequently, metaphase II (MII) oocytes were fertilized in vitro. In the experiment, the IVF medium was randomly divided into two equal groups: The control group did not receive any antioxidants. In the treatment group, 100 µM melatonin and 5 mM vitamin C were added to the IVF medium. Finally, oocytes and putative embryos transferred into developmental medium and cultured 120 h after IVF to the blastocyst stage. After and before IVF, oocytes and putative embryos were stained with dichlorodihydrofluorescein diacetate (DCFDA) and the H2O2 level was measured with an inverted fluorescence microscope using ImageJ software. At the end of the fifth day after IVF, the expression of Bax and B cell lymphoma 2 (Bcl2) was evaluated using real-time PCR.

RESULTS

The levels of reactive oxygen species (ROS) in oocytes and putative embryos observed in the treatment group demonstrated a significant reduce compared to the control group (p ≤ 0.01. (.Furthermore, the number of embryos in the blastocycte stage(P < 0.05), the expression level of the Bcl2 (P < 0.05) gene, the Bax unlike gene, significantly increased compared with the control group.

CONCLUSION

We conclude that the presence of melatonin and vitamin C antioxidants simultaneously and exclusively in the IVF medium leads to a reduction in ROS and ,as a result, improves the growth of the embryo up to the blastocyst stage.

Association between ambient air pollutants and birthweight of singletons following assisted reproductive technologies

OBJECTIVE

To investigate the associations between exposure to ambient air pollutants and birthweight following ART treatment.

DESIGN

Retrospective cohort study.

METHODS

We included 11,599 singletons derived from fresh cycles or frozen-thawed embryo transfer (FET) cycles between Jan 2013 and Dec 2019. Exposure to six air pollutants (SO2, NO2, CO, O3, PM2.5, and PM10) at patients` residences and the clinic site were estimated using the inverse distance weighting interpolation method based on data obtained from monitor sites. The daily mean levels of pollutants were estimated in potential exposure windows (the period from three months before treatment to oocyte retrieval, the period of ovarian stimulation, the period of in vitro culture, the period from embryo transfer to hCG test, the period of entire pregnancy, the 1st, 2nd, and 3rd trimester) were calculated. Generalized additive models adjusted for confounders including maternal age, BMI, and parity were used to evaluate the association between exposures and birthweight. Interaction of exposures and ART-associated factors, such as supraphysiologic estradiol and frozen-thawed, were explored in an XGboost model.

MAIN OUTCOME MEASURES

Birthweight and z-score of singletons.

RESULTS

In fresh cycles, O3 exposure during the period from three months before treatment to oocyte retrieval and SO2 exposure during in vitro culture at the ART clinic showed a linear association with birthweight (7.24, 95% CI: 1.18-13.31 g per 10 μg/m3 increase in O3; 25.92, 95% CI: 8.26-43.58 g per 10 μg/m3 increase in SO2, respectively). For patients receiving single blastocyst transfer with exposures below the China standard of 20 μg/m3, an increase of 10 μg/m3 in SO2 was associated with a 61.52 (95% CI: 1.13-121.91) g increase in birthweight. In FET cycles, no significant association was found between air pollution and birthweight. XGboost model did not reveal a strong interaction between the exposures and ART-related factors, except for the interactions between O3 exposure and BMI. However, none of the interactions reached a higher rank of importance.

CONCLUSIONS

Air pollution exposure during ART treatment may affect the birthweight of the offspring.

The mammalian preimplantation embryo: Its role in the environmental programming of postnatal health and performance

During formation of the preimplantation embryo several cellular and molecular milestones take place, making the few cells forming the early embryo vulnerable to environmental stressors than can impair epigenetic reprogramming and controls of gene expression. Although these molecular alterations can result in embryonic death, a significant developmental plasticity is present in the preimplantation embryo that promotes full-term pregnancy. Prenatal epigenetic modifications are inherited during mitosis and can perpetuate specific phenotypes during early postnatal development and adulthood. As such, the preimplantation phase is a developmental window where developmental programming can take place in response to the embryonic microenvironment present in vivo or in vitro. In this review, the relevance of the preimplantation embryo as a developmental stage where offspring health and performance can be programmed is discussed, with emphasis on malnutrition and assisted reproductive technologies; two major environmental insults with important implications for livestock production and human reproductive medicine.

Offspring physiology following the use of IVM, IVF and ICSI: a systematic review and meta-analysis of animal studies

BACKGROUND

Since the birth of the first baby using IVF technology in 1978, over 10 million children have been conceived via ART. Although most aspects of ARTs were developed in animal models, the introduction of these technologies into clinical practice was performed without comprehensive assessment of their long-term safety. The monitoring of these technologies over time has revealed differences in the physiology of babies produced using ARTs, yet due to the pathology of those presenting for treatment, it is challenging to separate the cause of infertility from the effect of treatments offered. The use of systematic review and meta-analysis to investigate the impacts of the predominant ART interventions used clinically in human populations on animals produced in healthy fertile populations offers an alternative approach to understanding the long-term safety of reproductive technologies.

OBJECTIVE AND RATIONALE

This systematic review and meta-analysis aimed to examine the evidence available from animal studies on physiological outcomes in the offspring conceived after IVF, IVM or ICSI, compared to in vivo fertilization, and to provide an overview on the landscape of research in this area.

SEARCH METHODS

PubMed, Embase and Commonwealth Agricultural Bureaux (CAB) Abstracts were searched for relevant studies published until 27 August 2021. Search terms relating to assisted reproductive technology, postnatal outcomes and mammalian animal models were used. Studies that compared postnatal outcomes between in vitro-conceived (IVF, ICSI or IVM) and in vivo-conceived mammalian animal models were included. In vivo conception included mating, artificial insemination, or either of these followed by embryo transfer to a recipient animal with or without in vitro culture. Outcomes included birth weight, gestation length, cardiovascular, metabolic and behavioural characteristics and lifespan.

OUTCOMES

A total of 61 studies in five different species (bovine, equine, murine, ovine and non-human primate) met the inclusion criteria. The bovine model was the most frequently used in IVM studies (32/40), while the murine model was mostly used in IVF (17/20) and ICSI (6/8) investigations. Despite considerable heterogeneity, these studies suggest that the use of IVF or maturation results in offspring with higher birthweights and a longer length of gestation, with most of this evidence coming from studies in cattle. These techniques may also impair glucose and lipid metabolism in male mice. The findings on cardiovascular outcomes and behaviour outcomes were inconsistent across studies.

WIDER IMPLICATIONS

Conception via in vitro or in vivo means appears to have an influence on measurable outcomes of offspring physiology, manifesting differently across the species studied. Importantly, it can be noted that these measurable differences are noticeable in healthy, fertile animal populations. Thus, common ART interventions may have long-term consequences for those conceived through these techniques, regardless of the pathology underpinning diagnosed infertility. However, due to heterogeneous methods, results and measured outcomes, highlighted in this review, it is difficult to draw firm conclusions. Optimizing animal and human studies that investigate the safety of new reproductive technologies will provide insight into safeguarding the introduction of novel interventions into the clinical setting. Cautiously prescribing the use of ARTs clinically may also be considered to reduce the chance of promoting adverse outcomes in children conceived before long-term safety is confidently documented.

Functional characterization of FBXL7 as a novel player in human cancers

F-box and leucine-rich repeat protein 7 (FBXL7), an F-box protein responsible for substrate recognition by the SKP1-Cullin-1-F-box (SCF) ubiquitin ligases, plays an emerging role in the regulation of tumorigenesis and tumor progression. FBXL7 promotes polyubiquitylation and degradation of diverse substrates and is involved in many biological processes, including apoptosis, cell proliferation, cell migration and invasion, tumor metastasis, DNA damage, glucose metabolism, planar cell polarity, and drug resistance. In this review, we summarize the downstream substrates and upstream regulators of FBXL7. We then discuss its role in tumorigenesis and tumor progression as either an oncoprotein or a tumor suppressor, and further describe its aberrant expression and association with patient survival in human cancers. Finally, we provide future perspectives on validating FBXL7 as a cancer biomarker for diagnosis and prognosis and/or as a potential therapeutic target for anticancer treatment.