The green tea polyphenol EGCG alleviates maternal diabetes-induced neural tube defects by inhibiting DNA hypermethylation

Dietary flavonoids prevent diabetes through epigenetic regulation: advance and challenge

The pathophysiology of diabetes has been studied extensively in various countries, but effective prevention and treatment methods are still insufficient. In recent years, epigenetics has received increasing attention from researchers in exploring the etiology and treatment of diabetes. DNA methylation, histone modifications, and non-coding RNAs play critical roles in the occurrence, maintenance, and progression of diabetes and its complications. Therefore, preventing or reversing the epigenetic alterations that occur during the development of diabetes may reduce the individual and societal burden of the disease. Dietary flavonoids serve as natural epigenetic modulators for the discovery of biomarkers for diabetes prevention and the development of alternative therapies. However, there is limited knowledge about the potential beneficial effects of flavonoids on the epigenetics of diabetes. In this review, the multidimensional epigenetic effects of different flavonoid subtypes in diabetes were summarized. Furthermore, it was discussed that parental flavonoid diets might reduce diabetes incidence in offspring, which represent a promising opportunity to prevent diabetes in the future. Future work will depend on exploring anti-diabetic effects of different flavonoids with different epigenetic regulation mechanisms and clinical trials.Highlights• "Epigenetic therapy" could reduce the burden of diabetic patients• "Epigenetic diet" ameliorates diabetes• Targeting epigenetic regulations by dietary flavonoids in the diabetes prevention• Dietary flavonoids prevent diabetes via transgenerational epigenetic inheritance.

Effects of dietary polyphenols on maternal and fetal outcomes in maternal diabetes

The incidences of short-term or long-term adverse maternal and fetal outcomes caused by maternal diabetes are increasing. Due to toxicity or side effects, economic pressures, and other problems associated with injections or oral hypoglycemic drugs, many researchers have investigated natural treatment methods. Polyphenols can protect against chronic pathologies by regulating numerous physiological processes and provide many health benefits. Moreover, polyphenols have anti-diabetic properties and can be used to treat diabetic complications. Diets rich in polyphenols are beneficial to pregnant women with diabetes. Here, we review the epidemiological and experimental evidence on the impact of dietary polyphenols on maternal and fetal outcomes in pregnant women with diabetes, and the effects of polyphenols on biological changes and possible mechanisms. Previous data (mainly from in vitro and animal experiments) showed that polyphenols can alleviate gestational diabetes mellitus and diabetic embryopathy by reducing maternal hyperglycemia and insulin resistance, alleviating inflammation and oxidative stress, and regulating related signaling pathways. Although polyphenols have shown many health benefits, further research is needed to better understand the complex interactions between polyphenols and maternal diabetes.

Common pregnancy complications and polyphenols intake: an overview

During pregnancy, the body undergoes a great amount of changes in order to support a healthy developing fetus. In this context, maternal dietary supplementation is widely encouraged to provide adequate nutrition for the newborn. In the past few years, studies have emerged highlighting the benefits of polyphenols intake during pregnancy. Indeed, despite differences among reports, such as experimental model, polyphenol employed, dosage and regimen of administration, there is no doubt that the ingestion of these molecules has a protective effect in relation to three pregnancy-associated diseases or conditions: preeclampsia, gestational diabetes and fetal growth restriction. In this review, we describe the effects of different polyphenols and polyphenol-rich extracts or juices on the main outcomes of these common pregnancy-associated complications, obtained in human, animal and in vitro studies. Therefore, this work provides a critical analysis of the literature, and a summary of evidences, from which future research using polyphenols can be designed and evaluated.

Effects of green tea polyphenol extract and epigallocatechin-3-O-gallate on diabetes mellitus and diabetic complications: Recent advances

Diabetes mellitus is one of the major non-communicable diseases accounting for millions of death annually and increasing economic burden. Hyperglycemic condition in diabetes creates oxidative stress that plays a pivotal role in developing diabetes complications affecting multiple organs such as the heart, liver, kidney, retina, and brain. Green tea from the plant Camellia sinensis is a common beverage popular in many countries for its health benefits. Green tea extract (GTE) is rich in many biologically active compounds, e.g., epigallocatechin-3-O-gallate (EGCG), which acts as a potent antioxidant. Recently, several lines of evidence have shown the promising results of GTE and EGCG for diabetes management. Here, we have critically reviewed the effects of GTE and EGCC on diabetes in animal models and clinical studies. The concerns and challenges regarding the clinical use of GTE and EGCG against diabetes are also briefly discussed. Numerous beneficial effects of green tea and its catechins, particularly EGCG, make this natural product an attractive pharmacological agent that can be further developed to treat diabetes and its complications.

The Role of Dietary Polyphenols in Pregnancy and Pregnancy-Related Disorders

Polyphenols are a group of phytochemicals with extensive biological functions and health-promoting potential. These compounds are present in most foods of plant origin and their increased widespread availability through the intake of nutritional supplements, fortified foods, and beverages, has also led to increased exposure throughout gestation. In this narrative review, we focus on the role of polyphenols in both healthy and pathological pregnancy. General information related to their classification and function is followed by an overview of their known effects in early-pregnancy events, including the current insights into molecular mechanisms involved. Further, we provide an overview of their involvement in some of the most common pregnancy-associated pathological conditions, such as preeclampsia and gestational diabetes mellitus. Additionally, we also discuss the estimated possible risk of polyphenol consumption on pregnancy outcomes. The consumption of dietary polyphenols during pregnancy needs particular attention considering the possible effects of polyphenols on the mechanisms involved in maternal adaptation and fetal development. Further studies are strongly needed to unravel the in vivo effects of polyphenol metabolites during pregnancy, as well as their role on advanced maternal age, prenatal nutrition, and metabolic risk of the offspring.

Synergistic Effects of Folic Acid and n-3 Polyunsaturated Fatty Acid in Preventing Neural Tube Defects in Diabetic Mice

The present study aimed to investigate whether a combination of folic acid (FA) and n-3 polyunsaturated fatty acids (PUFA) has a better preventive effect on maternal diabetes-induced neural tube defects (NTD) than FA alone. The experiment included five groups of pregnant mice: healthy control (HC), diabetes mellitus control (DMC), diabetes + n-3 PUFA (DMn-3), diabetes + FA (DMFA), and diabetes + FA + n-3 PUFA (DMFA + n-3). The incidence of NTD in DMFA + n-3 (1.04%) was significantly lower than that in DMFA (8.57%) and DMn-3 (7.82%). The incidence of NTD in DMFA and DMn-3 was significantly lower than that in DMC (19.41%). DMFA + n-3 had a lower apoptosis of neuroepithelial cells, a lower expression of P53 and Bax, and a higher expression of Pax3 and Bcl-2, compared with DMFA and DMn-3. Combination of FA and n-3 PUFA attenuated diabetes-induced hypermethylation of Pax3, overexpression and overactivity of Dnmt3b, abnormal expression of genes involved in one-carbon metabolism and elevation of homocysteine, and these improving effects were better than FA or n-3 PUFA alone. In conclusion, the combination of FA and n-3 PUFA has a synergistic effect on preventing maternal diabetes-induced NTD.

Tripeptide Leu-Pro-Phe from Corn Protein Hydrolysates Attenuates Hyperglycemia-Induced Neural Tube Defect in Chicken Embryos

Neural tube defect (NTD) is the most common and severe embryopathy causing embryonic malformation and even death associated with gestational diabetes mellitus (GDM). Leu-Pro-Phe (LPF) is an antioxidative tripeptide isolated from hydrolysates of corn protein. However, the biological activity of LPF in vivo and in vitro remains unclear. This study is aimed at investigating the protective effects of tripeptide LPF against NTD in the high glucose exposure condition and delineate the underlying biological mechanism. We found that LPF alleviated NTD in the high glucose-exposed chicken embryo model. In addition, DF-1 chicken embryo fibroblast was loaded with high glucose for induction of oxidative stress and abnormal O-GlcNAcylation in vitro. LPF significantly decreased accumulation of reactive oxygen species and content of malondialdehyde in DF-1 cells but increased the ratio of reduced glutathione and oxidized glutathione in chick embryo. Oxygen radical absorbance capacity results showed that LPF itself had good free radical scavenging capacity and could enhance antioxidant activity of the cell content. Mechanistic studies suggested that the resistance of LPF to oxidative damage may be related to promotion of NRF2 expression and nuclear translocation. LPF alleviated the overall O-GlcNAcylation level of cellular proteins under high glucose conditions and restored the level of Pax3 protein. Collectively, our findings indicate that LPF peptide could act as a nutritional supplement for the protection of development of embryonic neural tube affected by GDM.

Green Tea (Camellia sinensis): A Review of Its Phytochemistry, Pharmacology, and Toxicology

Objectives Green tea (Camellia sinensis) is a kind of unfermented tea that retains the natural substance in fresh leaves to a great extent. It is regarded as the second most popular drink in the world besides water. In this paper, the phytochemistry, pharmacology, and toxicology of green tea are reviewed systematically and comprehensively. Key findings Green tea has been demonstrated to be good for human health. Nowadays, multiple pharmacologically active components have been isolated and identified from green tea, including tea polyphenols, alkaloids, amino acids, polysaccharides, and volatile components. Recent studies have demonstrated that green tea shows versatile pharmacological activities, such as antioxidant, anticancer, hypoglycemic, antibacterial, antiviral, and neuroprotective. Studies on the toxic effects of green tea extract and its main ingredients have also raised concerns including hepatotoxicity and DNA damage. Summary Green tea can be used to assist the treatment of diabetes, Alzheimer’s disease, oral cancer, and dermatitis. Consequently, green tea has shown promising practical prospects in health care and disease prevention.

Exploring epigenomic mechanisms of neural tube defects using multi-omics methods and data

Neural tube defects (NTDs) are a heterogeneous set of malformations attributed to disruption in normal neural tube closure during early embryogenesis. An in-depth understanding of NTD etiology and mechanisms remains elusive, however. Among the proposed mechanisms, epigenetic changes are thought to play an important role in the formation of NTDs. Epigenomics covers a wide spectrum of genomic DNA sequence modifications that can be investigated via high-throughput techniques. Recent advances in epigenomic technologies have enabled epigenetic studies of congenital malformations and facilitated the integration of big data into the understanding of NTDs. Herein, we review clinical epigenomic data that focuses on DNA methylation, histone modification, and miRNA alterations in human neural tissues, placental tissues, and leukocytes to explore potential mechanisms by which candidate genes affect human NTD pathogenesis. We discuss the links between epigenomics and gene regulatory mechanisms, and the effects of epigenetic alterations in human tissues on neural tube closure.

Epigenetics provides a bridge between early nutrition and long-term health and a target for disease prevention

Exposure to nutritional imbalance during early life can influence disease risk lifelong and across generations. In this long‐term conditioning, epigenetics constitutes a key mechanism. They bridge environmental cues and the expression of genes involved in the setting of long‐standing biological regulations in numerous organs and species. Epigenetic marks are proposed as innovative diagnostic biomarkers and potential targets in the prevention of diseases. However, a number of uncertainties make them difficult to use in clinical approaches in the context of early exposure to nutritional challenge. In conclusion, active investigations in this field are still needed before clinical applications are considered.

Painful Diabetic Neuropathy Is Associated with Compromised Microglial IGF-1 Signaling Which Can Be Rescued by Green Tea Polyphenol EGCG in Mice

Background

Painful diabetic neuropathy (PDN) is a frequent and troublesome complication of diabetes, with little effective treatment. PDN is characterized by specific spinal microglia-mediated neuroinflammation. Insulin-like growth factor 1 (IGF-1) primarily derives from microglia in the brain and serves a vital role in averting the microglial transition into the proinflammatory M1 phenotype. Given that epigallocatechin-3-gallate (EGCG) is a potent anti-inflammatory agent that can regulate IGF-1 signaling, we speculated that EGCG administration might reduce spinal microglia-related neuroinflammation and combat the development of PDN through IGF-1/IGF1R signaling.

Methods

Type 1 diabetes mellitus (T1DM) was established by a single intraperitoneal (i.p.) injection of streptozotocin (STZ) in mice. The protein expression level of IGF-1, its receptor IGF1R, interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) was determined by Western blot or immunofluorescence.

Results

The spinal IGF-1 expression markedly decreased along with the presence of pain-like behaviors, the spinal genesis of neuroinflammation (increased IL-1β, TNF-α, and Iba-1⁺ microglia), and the intensified M1 microglia polarization (increased iNOS⁺Iba-1⁺ microglia) in diabetic mice. IGF-1 could colocalize with neurons, astrocytes, and microglia, but only microglial IGF-1 was repressed in T1DM mice. Furthermore, we found that i.t. administration of mouse recombinant IGF-1 (rIGF-1) as well as i.t. or i.p. treatment with EGCG alleviated the diabetes-induced pain-like behaviors, reduced neuroinflammation (suppressed IL-1β, TNF-α, and Iba-1⁺ microglia), prevented the M1 microglia polarization (less iNOS⁺Iba-1⁺ microglia), and restored the microglial IGF-1 expression.

Conclusions

Our data highlighted the importance of maintaining spinal IGF-1 signaling in treating microglia-related neuroinflammation in PDN. This study also provides novel insights into the neuroprotective mechanisms of EGCG against neuropathic pain and neuroinflammation through IGF-1 signaling, indicating that this agent may be a promising treatment for PDN in the clinical setting.

The Efficacy Mechanism of Epigallocatechin Gallate against Pre-Eclampsia based on Network Pharmacology and Molecular Docking

Pre-eclampsia (PE), a pregnancy complication, affects 3-5% of all pregnancies worldwide and is the main cause of maternal and perinatal morbidity. However, there is no drug which can clearly slow this disease progression. Epigallocatechin gallate (EGCG), a natural compound extracted from green tea, has been found to enhance the treatment efficacy of oral nifedipine against pregnancy-induced severe PE. This study aims to clarify the potential targets and pharmacological mechanisms of EGCG in treatment of PE. We used Traditional Chinese Medicine Systems Pharmacology database and Gene Cards database to obtain 179 putative target proteins of EGCG, 550 PE-related hub genes and 39 intersecting targets between EGCG and PE. By using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, we got the gene entries and enrichment pathways closely related to the intersecting targets. The top 10 enrichment pathways were pathway in cancer, proteoglycans in cancer, HIF-1 signaling pathway, AGE-RAGE signaling pathway in diabetic complications, TNF signaling pathway, bladder cancer, hepatitis B, IL-17 signaling pathway, toxoplasmosis, PI3K-Akt signaling pathway. Furthermore, compound-target-pathway (CTP) and protein-protein interaction (PPI) network analysis were employed to explore the interaction of the top twelve targets for EGCG in treating PE. Molecular docking analysis showed combinations between these targets and EGCG, and the interaction between EGCG and the targets IL-6 and EGFR was confirmed by using molecular dynamic simulation. In conclusion, these findings hint the underlying mechanism of EGCG in the treatment of PE and point out directions in further studies on PE.

The Impact of EGCG and RG108 on SOCS1 Promoter DNA Methylation and Expression in U937 Leukemia Cells

BACKGROUND

The available evidence has increasingly demonstrated that a combination of genetic and epigenetic factors, such as DNA methylation, could be considered as causing leukemia. Epigenetic changes and methylation of the suppressor of the cytokine signaling 1 promoter (SOCS1) CpG region silence SOCS1 expression in cancer. In the current study, we evaluated the impact of epigallocatechin gallate (EGCG) and RG108 on SOCS1 promoter methylation and expression in U937 cells.

METHODS

In the current study, U937 leukemic cells were treated with EGCG and RG108 for 12, 24, 48, and 72 h and SOCS1 promoter methylation and its expression were measured by methylation-specific PCR (MSP) and quantitative real-time PCR, respectively.

RESULTS

The outcomes indicated that the SOCS1 promoter is methylated in U937 cells, and treatment of these cells with either EGCG or RG108 reduced its methylation. Moreover, we observed that SOCS1 expression was significantly upregulated in a time-dependent manner by both EGCG and RG108 in U937 cells compared with control cells. In the RG108-treated group at 12, 24, 48, and 72 h, SOCS1 expression was upregulated by 1, 4.2, 16.6, and 32.6 -fold respectively, and in the EGCG-treated group, by 0.5, 3.2, 10.8, and 22.3 -fold, respectively.

CONCLUSION

Treatment with either EGCG or RG108 reduced SOCS1 promoter methylation and increased SOCS1 expression in U937 cells in a time-dependent manner, which may play a role in leukemia therapy.

Green tea and metabolic syndrome: A 10-year research update review

Metabolic syndrome (MetS) has turned into a prevalent condition that has imposed a tremendous financial strain on public health care systems. It is believed that the MetS consists of four main factors (hypertension, dyslipidemia, hyperglycemia, and obesity) and may lead to cardiovascular events. Camellia sinesis, in the form of green tea (GT), is one of the most consuming beverages worldwide. Catechins are the dominant component of green tea leaves. Epigallocatechin gallate has the maximum potency. GT has been widely used as a supplement in various health conditions. As the oxidative stress pathway is one of the probable mechanisms of MetS etiologies and GT beneficial effects, GT may be a novel strategy to overcome the MetS. This review aims to reveal the probable pharmacological effects of GT on MetS. The last 10-year original articles on MetS parameters and GT have been gathered in this review. This manuscript has summarized the probable effects of green tea and its catechins on MetS and focused on each different aspect of MetS separately, which can be used as a basis for further investigations for introducing effective compounds as a way to interfere with MetS.

It seems that GT can reduce MetS parameters commonly via anti-inflammatory and anti-oxidative mechanisms. Further clinical trials are needed to confirm the use of GT and its constituents for the treatment of MetS.

The link among microbiota, epigenetics, and disease development

The microbiome is a community of various microorganisms that inhabit or live on the skin of humans/animals, sharing the body space with their hosts. It is a sort of complex ecosystem of trillions of commensals, symbiotic, and pathogenic microorganisms, including trillions of bacteria, archaea, protozoa, fungi, and viruses. The microbiota plays a role in the health and disease status of the host. Their number, species dominance, and viability are dynamic. Their long-term disturbance is usually accompanied by serious diseases such as metabolic disorders, cardiovascular diseases, or even cancer. While epigenetics is a term that refers to different stimuli that induce modifications in gene expression patterns without structural changes in the inherited DNA sequence, these changes can be reversible or even persist for several generations. Epigenetics can be described as cell memory that stores experience against internal and external factors. Results from multiple institutions have contributed to the role and close interaction of both microbiota and epigenetics in disease induction. Understanding the mechanisms of both players enables a better understanding of disease induction and development and also opens the horizon to revolutionary therapeutic approaches. The present review illustrates the roles of diet, microbiome, and epigenetics in the induction of several chronic diseases. In addition, it discusses the application of epigenetic data to develop diagnostic biomarkers and therapeutics and evaluate their safety for patients. Understanding the interaction among all these elements enables the development of innovative preventive/therapeutic approaches for disease control.

Epigenetic regulation by polyphenols in diabetes and related complications

Diabetes mellitus (DM) is a chronic metabolic disorder and one of the most challenging health problems worldwide. Left untreated, it may progress causing serious complications. Genetics, epigenetics, and environmental factors are known to play an overlapping role in the pathogenesis of DM. Growing evidence suggests the hypothesis that the environment induces changes in the early phases of growth and development, influencing health and disease in the adulthood through the alteration in genetic expression of an individual, at least in part. DNA methylation, histone modifications and miRNAs are three mechanisms responsible for epigenetic alterations. The daily diet contains a number of secondary metabolites, with polyphenols being highest in abundance, which contribute to overall health and may prevent or delay the onset of many chronic diseases. Polyphenols have the ability to alter metabolic and signaling pathways at various levels, such as gene expression, epigenetic regulation, protein expression and enzyme activity. The potential efficacy of polyphenolic compounds on glucose homeostasis has been evidenced from in vitro, in vivo and clinical studies. The present review is designed to focus on epigenetic regulation exerted by polyphenolic compounds in DM and their complications, as well as to summarize clinical trials involving polyphenols in DM.

Deficiency of the oxidative stress-responsive kinase p70S6K1 restores autophagy and ameliorates neural tube defects in diabetic embryopathy

BACKGROUND

Autophagy is highly active in neuroepithelial cells of the developing neuroepithelium, and impairment of autophagy leads to neural tube defects. In this study, we have found that maternal diabetes suppresses autophagy that leads to neural tube defects and consequent cellular imbalance in the endoplasmic reticulum where critical events occur, leading to the induction of diabetic embryopathy. Because the mammalian target of rapamycin pathway suppresses autophagy, we hypothesized that 70 kDa ribosomal protein S6 kinase 1 (p70S6K1), a major downstream effector of mammalian target of rapamycin, mediates the inhibitory effect of maternal diabetes on autophagy in the developing neuroepithelium.

OBJECTIVE

We investigated whether p70S6K1 mediates the inhibitory effect of maternal diabetes on autophagy during neurulation. We also examined whether p70S6K1 deficiency restores autophagy and therefore relieves endoplasmic reticulum stress and inhibits maternal diabetes-induced apoptosis, which leads to reduction in neural tube defect incidence in diabetic embryopathy.

STUDY DESIGN

Female p70S6K1 heterogeneous knockout (p70S6K1+/-) mice were bred with male p70S6K1 heterogeneous knockout (p70S6K1+/-) mice to generate wild-type (WT), p70S6K1+/- and p70S6K1 knockout (p70S6K1-/-) embryos. Embryos at embryonic day 8.5 were harvested for the assessment of indices of autophagy, endoplasmic reticulum stress, and apoptosis. Neural tube defect incidence in embryos was determined at embryonic day 10.5. For in vitro studies, small interfering RNA knockdown of p70S6K1 in C17.2 mouse neural stem cells was used to determine the effect of p70S6K1 deficiency on autophagy impairment and endoplasmic reticulum stress under high glucose conditions.

RESULTS

Knockout of the Rps6kb1 gene, which encodes for p70S6K1, ameliorated maternal diabetes-induced NTDs and restored autophagosome formation in neuroepithelial cells suppressed by maternal diabetes. Maternal diabetes-suppressed conversion of LC3-I (microtubule-associated protein 1A/1B-light chain 3) to LC3-II, an index of autophagic activity, in neurulation stage embryos was abrogated in the absence of p70S6K1. p70S6K1 knockdown in neural stem cells also restored autophagosome formation and the conversion of LC3-I to LC3-II. The activation of the major unfolded protein response, indicated by phosphorylation of inositol-requiring enzyme 1 alpha, and protein kinase R-like endoplasmic reticulum kinase, and eukaryotic translation initiation factor 2α, and the increase of the endoplasmic reticulum stress marker, C/EBP homologous protein, were induced by maternal diabetes in vivo and high glucose in vitro. Unfolded protein response and endoplasmic reticulum stress induced by maternal diabetes or high glucose were reduced by Rps6kb1 deletion or p70S6K1 knockdown, respectively. Rps6kb1 knockout blocked maternal diabetes-induced caspase cleavage and neuroepithelial cell apoptosis. The superoxide dismutase mimetic Tempol abolished high glucose-induced p70S6K1 activation.

CONCLUSION

The study revealed the critical involvement of p70S6K1 in the pathogenesis of diabetic embryopathy.

Restoring BMP4 expression in vascular endothelial progenitors ameliorates maternal diabetes-induced apoptosis and neural tube defects

During mouse embryonic development, vasculogenesis initially occurs in the yolk sac, preceding neurulation. Our previous studies have demonstrated that maternal diabetes induces embryonic vasculopathy at early embryonic developmental stage by suppressing the expression of vascular growth factors including BMP4 (bone morphogenetic protein 4). This study aimed to determine whether restoring diabetes-inhibited BMP4 expression in Flk-1+ progenitors effectively prevented maternal diabetes-induced embryonic vasculopathy and NTDs. Transgenic (Tg) BMP4 expression in the vascular endothelial growth factor receptor 2 (Flk-1)-positive (Flk-1+) progenitors was achieved by crossing a Floxed BMP4 Tg mouse line with the Flk-1-Cre mouse line. Non-BMP4 Tg and BMP4 Tg embryos were harvested at E8.5 to assess the expression of BMP4, markers of endoplasmic reticulum stress, and expression of the Id genes, direct targets of BMP4; and the presence of cleaved caspase 3 and 8, apoptosis, and Smad signaling. BMP4 Tg overexpression neutralized its down-regulation by maternal diabetes in E8.5 embryos. Maternal diabetes-induced Flk-1+ progenitor apoptosis, impairment of blood island formation, and reduction of Flk-1+ progenitor number and blood vessel density, which were reversed by BMP4 Tg expression. BMP4 Tg expression in Flk-1+ progenitors blocked maternal diabetes-induced vasculopathy in early stage embryos (E7.5-E8.5) and consequently led to amelioration of maternal diabetes-induced neural tube defects (NTDs) at E10.5. BMP4 Tg expression inhibited maternal diabetes-induced endoplasmic reticulum stress and caspase cascade activation in the developing neuroepithelium, and reduced neuroepithelial cell apoptosis. BMP4 Tg expression re-activated Smad1/5/8 phosphorylation and reversed maternal diabetes-suppressed Smad4 expression. BMP4 Tg expression restored Id1 and Smad6 expression inhibited by maternal diabetes. In vitro, recombinant BMP4 protein blocked high glucose-induced Flk-1+ progenitor apoptosis and NTDs. These data demonstrate that BMP4 down-regulation in Flk-1+ progenitors are responsible for diabetes-induced yolk sac vasculopathy, and that restoring BMP4 expression prevents vasculopathy and rescues neuroepithelial cells from cellular organelle stress, leading to NTD reduction.

The Evolving Role of Natural Compounds in the Medical Treatment of Uterine Fibroids

Uterine fibroids (UFs) remain a significant health issue for many women, with a disproportionate impact on women of color, likely due to both genetic and environmental factors. The prevalence of UFs is estimated to be approximately 70% depending on population. UF-derived clinical symptoms include pelvic pain, excessive uterine bleeding, gastrointestinal and voiding problems, as well as impaired fertility. Nowadays numerous methods of UF treatment are available-from conservative treatment to invasive surgeries. Selecting an appropriate treatment option should be individualized and adjusted to the patient's expectations as much as possible. So far, the mainstay of treatment is surgery, but their negative impact of future fertility is clear. On the other hand, emerging new pharmaceutical options have significant adverse effects like liver function impairment, hot flashes, bone density loss, endometrial changes, and inability to attempt conception during treatment. Several natural compounds are found to help treat UFs and relieve their symptoms. In this review we summarize all the current available data about natural compounds that may be beneficial for patients with UFs, especially those who want to preserve their future fertility or have treatment while actively pursuing conception. Vitamin D, epigallocatechin gallate, berberine, curcumin, and others are being used as alternative UF treatments. Moreover, we propose the concept of using combined therapies of natural compounds on their own or combined with hormonal agents to manage UFs. There is a strong need for more human clinical trials involving these compounds before promoting widespread usage.

Dietary natural products as epigenetic modifiers in aging-associated inflammation and disease

Covering: up to 2020Chronic, low-grade inflammation is linked to aging and has been termed "inflammaging". Inflammaging is considered a key contributor to the development of metabolic dysfunction and a broad spectrum of diseases or disorders including declines in brain and heart function. Genome-wide association studies (GWAS) coupled with epigenome-wide association studies (EWAS) have shown the importance of diet in the development of chronic and age-related diseases. Moreover, dietary interventions e.g. caloric restriction can attenuate inflammation to delay and/or prevent these diseases. Common themes in these studies entail the use of phytochemicals (plant-derived compounds) or the production of short chain fatty acids (SCFAs) as epigenetic modifiers of DNA and histone proteins. Epigenetic modifications are dynamically regulated and as such, serve as potential therapeutic targets for the treatment or prevention of age-related disease. In this review, we will focus on the role for natural products that include phytochemicals and short chain fatty acids (SCFAs) as regulators of these epigenetic adaptations. Specifically, we discuss regulators of methylation, acetylation and acylation, in the protection from chronic inflammation driven metabolic dysfunction and deterioration of neurocognitive and cardiac function.

Preclinical Pharmacological Activities of Epigallocatechin-3-gallate in Signaling Pathways: An Update on Cancer

Epigallocatechin gallate (EGCG) is the main bioactive component of catechins predominantly present in svarious types of teas. EGCG is well known for a wide spectrum of biological activity as an anti-oxidative, anti-inflammatory, and anti-tumor agent. The effect of EGCG on cell death mechanisms via the induction of apoptosis, necrosis, and autophagy has been documented. Moreover, its anti-proliferative and chemopreventive action has been demonstrated in many cancer cell lines. It was also involved in the modulation of cyclooxygenase-2, in oxidative stress and inflammation of different cell processes. EGCG has been reported as a promising target for plasma membrane proteins, such as epidermal growth factor receptor (EGFR). In addition, it has been demonstrated a mechanism of action relying on the inhibition of ERK1/2, p38 MAPK, NF-κB, and vascular endothelial growth factor (VEGF). EGCG and its derivatives were used in proteasome inhibition and they were involved in epigenetic mechanisms. In summary, EGCG is the most predominant and bioactive constituent of teas and it has a pivotal role in cancer prevention. Its preclinical pharmacological activities are associated with complex molecular mechanisms that involve numerous signaling pathways.

Kombucha from alternative raw materials - The review

Nowadays, people's awareness about the role of diet in maintaining well-being and good health has increased. Consumers expect that the products not only provide them with essential nutrients but will also be a source of biologically active substances, which are beneficial to their health. One of the "healthy trends," which has appeared among the consumers worldwide is kombucha, a tea drink with high antioxidant potential, obtained through the activity of a consortium of acetic acid bacteria and osmophilic yeast, which is also called "tea fungus." Kombucha obtained from tea is characterized by its health-promoting properties. Promising results in in vitro and in vivo studies have prompted research groups from around the world to search for alternative raw materials for tea fungus fermentation. Attempts are made to obtain functional beverages from leaves, herb infusions, vegetable pulp, fruit juices, or milk. This review focuses on describing the progress in obtaining a fermented beverage and bacterial cellulose using tea fungus on alternative raw materials.

Effects and Mechanisms of Tea for the Prevention and Management of Diabetes Mellitus and Diabetic Complications: An Updated Review

Diabetes mellitus has become a serious and growing public health concern. It has high morbidity and mortality because of its complications, such as diabetic nephropathy, diabetic cardiovascular complication, diabetic neuropathy, diabetic retinopathy, and diabetic hepatopathy. Epidemiological studies revealed that the consumption of tea was inversely associated with the risk of diabetes mellitus and its complications. Experimental studies demonstrated that tea had protective effects against diabetes mellitus and its complications via several possible mechanisms, including enhancing insulin action, ameliorating insulin resistance, activating insulin signaling pathway, protecting islet β-cells, scavenging free radicals, and decreasing inflammation. Moreover, clinical trials also confirmed that tea intervention is effective in patients with diabetes mellitus and its complications. Therefore, in order to highlight the importance of tea in the prevention and management of diabetes mellitus and its complications, this article summarizes and discusses the effects of tea against diabetes mellitus and its complications based on the findings from epidemiological, experimental, and clinical studies, with the special attention paid to the mechanisms of action.

Aberrant methylation of Pax3 gene and neural tube defects in association with exposure to polycyclic aromatic hydrocarbons

BACKGROUND

Neural tube defects (NTDs) are common and severe congenital malformations. Pax3 is an essential gene for neural tube closure in mice but it is unknown whether altered expression or methylation of PAX3 contributes to human NTDs. We examined the potential role of hypermethylation of Pax3 in the development of NTDs by analyzing human NTD cases and a mouse model in which NTDs were induced by benzo[a]pyrene (BaP), a widely studied polycyclic aromatic hydrocarbon (PAH).

METHODS

We extracted methylation information of PAX3 in neural tissues from array data of ten NTD cases and eight non-malformed controls. A validation study was then performed in a larger independent population comprising 73 NTD cases and 29 controls. Finally, we examined methylation patterns and expression of Pax3 in neural tissues from mouse embryos of dams exposed to BaP or BaP and vitamin E.

RESULTS

Seven CpG sites in PAX3 were hypermethylated in NTD fetuses as compared to controls in the array data. In the validation phase, significantly higher methylation levels in the body region of PAX3 were observed in NTD cases than in controls (P = 0.003). And mean methylation intensity in the body region of PAX3 in fetal neural tissues was positively correlated with median concentrations of PAH in maternal serum. In the mouse model, BaP-induced NTDs were associated with hypermethylation of specific CpG sites within both the promoter and body region of Pax3. Supplementation with vitamin E via chow decreased the rate of NTDs, partly recovered the repressed total antioxidant capacity in mouse embryos exposed to BaP, and this was accompanied by the normalization of Pax3 methylation level and gene expression.

CONCLUSION

Hypermethylation of Pax3 may play a role in the development of NTDs; DNA methylation aberration may be caused by exposure to BaP, with possible involvement of oxidative stress.

The increased activity of a transcription factor inhibits autophagy in diabetic embryopathy

BACKGROUND

Maternal diabetes induces neural tube defects and stimulates the activity of the forkhead box O3 (Fox)O3a in the embryonic neuroepithelium. We previously demonstrated that deleting the FOXO3a gene ameliorates maternal diabetes-induced neural tube defects. Macroautophagy (hereafter referred to as "autophagy") is essential for neurulation. Rescuing autophagy suppressed by maternal diabetes in the developing neuroepithelium inhibits neural tube defect formation in diabetic pregnancy. This evidence suggests a possible link between FoxO3a and impaired autophagy in diabetic embryopathy.

OBJECTIVE

We aimed to determine whether maternal diabetes suppresses autophagy through FoxO3a, and if the transcriptional activity of FoxO3a is required for the induction of diabetic embryopathy.

STUDY DESIGN

We used a well-established type 1 diabetic embryopathy mouse model, in which diabetes was induced by streptozotocin, for our in vivo studies. To determine if FoxO3a mediates the inhibitory effect of maternal diabetes on autophagy in the developing neuroepithelium, we induced diabetic embryopathy in FOXO3a gene knockout mice and FoxO3a dominant negative transgenic mice. Embryos were harvested at embryonic day 8.5 to determine FoxO3a and autophagy activity and at embryonic day 10.5 for the presence of neural tube defects. We also examined the expression of autophagy-related genes. C17.2 neural stem cells were used for in vitro examination of the potential effects of FoxO3a on autophagy.

RESULTS

Deletion of the FOXO3a gene restored the autophagy markers, lipidation of microtubule-associated protein 1A/1B-light chain 3I to light chain 3II, in neurulation stage embryos. Maternal diabetes decreased light chain 3I-positive puncta number in the neuroepithelium, which was restored by deleting FoxO3a. Maternal diabetes also decreased the expression of positive regulators of autophagy (Unc-51 like autophagy activating kinase 1, Coiled-coil myosin-like BCL2-interacting protein, and autophagy-related gene 5) and the negative regulator of autophagy, p62. FOXO3a gene deletion abrogated the dysregulation of autophagy genes. In vitro data showed that the constitutively active form of FoxO3a mimicked high glucose in repressing autophagy. In cells cultured under high-glucose conditions, overexpression of the dominant negative FoxO3a mutant blocked autophagy impairment. Dominant negative FoxO3a overexpression in the developing neuroepithelium restored autophagy and significantly reduced maternal diabetes-induced apoptosis and neural tube defects.

CONCLUSION

Our study revealed that diabetes-induced FoxO3a activation inhibited autophagy in the embryonic neuroepithelium. We also observed that FoxO3a transcriptional activity mediated the teratogenic effect of maternal diabetes because dominant negative FoxO3a prevents maternal diabetes-induced autophagy impairment and neural tube defect formation. Our findings suggest that autophagy activators could be therapeutically effective in treating maternal diabetes-induced neural tube defects.

Epigenetic Mechanisms Link Maternal Diets and Gut Microbiome to Obesity in the Offspring

Nutrition is the most important environmental factor that can influence early developmental processes through regulation of epigenetic mechanisms during pregnancy and neonatal periods. Maternal diets or nutritional compositions contribute to the establishment of the epigenetic profiles in the fetus that have a profound impact on individual susceptibility to certain diseases or disorders in the offspring later in life. Obesity is considered a global epidemic that impairs human life quality and also increases risk of development of many human diseases such as diabetes and cardiovascular diseases. Studies have shown that maternal nutrition status is closely associated with obesity in progenies indicating obesity has a developmental origin. Maternal diets may also impact the early establishment of the fetal and neonatal microbiome leading to specific epigenetic signatures that may potentially predispose to the development of late-life obesity. This article will review the association of different maternal dietary statuses including essential nutritional quantity and specific dietary components with gut microbiome in determining epigenetic impacts on offspring susceptibility to obesity.

Endoplasmic Reticulum Stress-Induced CHOP Inhibits PGC-1α and Causes Mitochondrial Dysfunction in Diabetic Embryopathy

Endoplasmic reticulum (ER) stress has been implicated in the development of maternal diabetes-induced neural tube defects (NTDs). ER stress-induced C/EBP homologous protein (CHOP) plays an important role in the pro-apoptotic execution pathways. However, the molecular mechanism underlying ER stress- and CHOP-induced neuroepithelium cell apoptosis in diabetic embryopathy is still unclear. Deletion of the Chop gene significantly reduced maternal diabetes-induced NTDs. CHOP deficiency abrogated maternal diabetes-induced mitochondrial dysfunction and neuroepithelium cell apoptosis. Further analysis demonstrated that CHOP repressed the expression of peroxisome-proliferator-activated receptor-γ coactivator-1α (PGC-1α), an essential regulator for mitochondrial biogenesis and function. Both CHOP deficiency in vivo and knockdown in vitro restore high glucose-suppressed PGC-1α expression. In contrast, CHOP overexpression mimicked inhibition of PGC-1α by high glucose. In response to the ER stress inducer tunicamycin, PGC-1α expression was decreased, whereas the ER stress inhibitor 4-phenylbutyric acid blocked high glucose-suppressed PGC-1α expression. Moreover, maternal diabetes in vivo and high glucose in vitro promoted the interaction between CHOP and the PGC-1α transcriptional regulator CCAAT/enhancer binding protein-β (C/EBPβ), and reduced C/EBPβ binding to the PGC-1α promoter leading to markedly decrease in PGC-1α expression. Together, our findings support the hypothesis that maternal diabetes-induced ER stress increases CHOP expression which represses PGC-1α through suppressing the C/EBPβ transcriptional activity, subsequently induces mitochondrial dysfunction and ultimately results in NTDs.

Pregestational type 2 diabetes mellitus induces cardiac hypertrophy in the murine embryo through cardiac remodeling and fibrosis

BACKGROUND

Cardiac hypertrophy is highly prevalent in patients with type 2 diabetes mellitus. Experimental evidence has implied that pregnant women with type 2 diabetes mellitus and their children are at an increased risk of cardiovascular diseases. Our previous mouse model study revealed that maternal type 2 diabetes mellitus induces structural heart defects in their offspring.

OBJECTIVE

This study aims to determine whether maternal type 2 diabetes mellitus induces embryonic heart hypertrophy in a murine model of diabetic embryopathy.

STUDY DESIGN

The type 2 diabetes mellitus embryopathy model was established by feeding 4-week-old female C57BL/6J mice with a high-fat diet for 15 weeks. Cardiac hypertrophy in embryos at embryonic day 17.5 was characterized by measuring heart size and thickness of the right and left ventricle walls and the interventricular septum, as well as the expression of β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, desmin, and adrenomedullin. Cardiac remodeling was determined by collagen synthesis and fibronectin synthesis. Fibrosis was evaluated by Masson staining and determining the expression of connective tissue growth factor, osteopontin, and galectin-3 genes. Cell apoptosis also was measured in the developing heart.

RESULTS

The thicknesses of the left ventricle walls and the interventricular septum of embryonic hearts exposed to maternal diabetes were significantly thicker than those in the nondiabetic group. Maternal diabetes significantly increased β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, and desmin expression, but decreased expression of adrenomedullin. Moreover, collagen synthesis was significantly elevated, whereas fibronectin synthesis was suppressed, in embryonic hearts from diabetic dams, suggesting that cardiac remodeling is a contributing factor to cardiac hypertrophy. The cardiac fibrosis marker, galectin-3, was induced by maternal diabetes. Furthermore, maternal type 2 diabetes mellitus activated the proapoptotic c-Jun-N-terminal kinase 1/2 stress signaling and triggered cell apoptosis by increasing the number of terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling-positive cells (10.4 ± 2.2% of the type 2 diabetes mellitus group vs 3.8 ± 0.7% of the nondiabetic group, P < .05).

CONCLUSION

Maternal type 2 diabetes mellitus induces cardiac hypertrophy in embryonic hearts. Adverse cardiac remodeling, including elevated collagen synthesis, suppressed fibronectin synthesis, profibrosis, and apoptosis, is implicated as the etiology of cardiac hypertrophy.

Abnormal Placentation Associated with Infertility as a Marker of Overall Health

Infertility and fertility treatments utilized are associated with abnormal placentation leading to adverse pregnancy outcomes related to placentation, including preterm birth, low birth weight, placenta accrete, and placenta previa. This may be due to the underlying genetics predisposing to infertility or the epigenetic changes associated with the fertility treatments utilized, as specific disease states leading to infertility are at increased risk of adverse outcomes, including placental abruption, fetal loss, gestational diabetes mellitus, and outcomes related to placentation, as well as the treatments utilized including in vitro fertilization (IVF) and non-IVF fertility treatment. Placentation defects, leading to adverse maternal and fetal outcomes, which are more pronounced in the infertile population, occur due to changes in trophoblast invasion, vascular defects, changes in the environmental milieu, chronic inflammation, and oxidative stress. These similar processes are recognized as major contributors to lifelong risk of cardiovascular and metabolic disease for both the mother and her offspring. Thus, abnormal placentation, found to be more prevalent in the infertile population, may be the key to better understand how infertility affects overall and long-term health.

Neurobehavioral changes in mice offspring exposed to green tea during fetal and early postnatal development

BACKGROUND

Green tea extract (GTE) has various health promoting effects on animals and humans. However, the effects of perinatal exposure to GTE on the behavioral aspects of offspring have not been elucidated thus far. GTE was provided for pregnant female mice at concentrations of either 20 or 50 g/L, beginning the day of conception until the third week after delivery, postnatal day 22 (PD 22). Mice pups were subjected to behavioral testing to assess sensory motor reflexes, locomotion, anxiety, and learning on various postnatal days.

RESULTS

Perinatal exposure to GTE resulted in a significant reduction in body weight, as well as earlier body hair appearance and opening of the eyes. Sensory motor reflexes exhibited faster responses and significant stimulatory effects in pups exposed to GTE. During the adolescent period, male and female offspring exhibited increased locomotor activity (on PD 22), reduced anxiety and fear (on PD 25), and enhanced memory and learning abilities (on PD 30), all in both GTE treated groups. All blood counts (RBCs, WBCs, Hb, and platelets), and glucose, cholesterol, triglyceride, and low density lipoprotein concentrations were significantly lower in the GTE-treated pups; however, there was no effect on high density lipoprotein levels.

CONCLUSION

Our data provide evidence that the high dose of GTE (50 g/L) had higher anxiolytic properties and positive effects on locomotor activities and sensory motor reflexes, as well as learning and memory of the offspring than the low dose of GTE (20 g/L).

Maternal diabetes and high glucose in vitro trigger Sca1+ cardiac progenitor cell apoptosis through FoxO3a

Recent controversies surrounding the authenticity of c-kit⁺ cardiac progenitor cells significantly push back the advance in regenerative therapies for cardiovascular diseases. There is an urgent need for research in characterizing alternative types of cardiac progenitor cells. Towards this goal, in the present study, we determined the effect of maternal diabetes on Sca1⁺ cardiac progenitor cells. Maternal diabetes induced caspase 3-dependent apoptosis in Sca1⁺ cardiac progenitor cells derived from embryonic day 17.5 (E17.5). Similarly, high glucose in vitro but not the glucose osmotic control mannitol triggered Sca1⁺ cardiac progenitor cell apoptosis in a dose- and time-dependent manner. Both maternal diabetes and high glucose in vitro activated the pro-apoptotic transcription factor, Forkhead O 3a (FoxO3a) via dephosphorylation at threonine 32 (Thr-32) residue. foxo3a gene deletion abolished maternal diabetes-induced Sca1⁺ cardiac progenitor cell apoptosis. The dominant negative FoxO3a mutant without the transactivation domain from the C terminus blocked high glucose-induced Sca1⁺ cardiac progenitor cell apoptosis, whereas the constitutively active FoxO3a mutant with the three phosphorylation sites, Thr-32, Ser-253, and Ser-315, being replaced by alanine residues mimicked the pro-apoptotic effect of high glucose. Thus, maternal diabetes and high glucose in vitro may limit the regenerative potential of Sca1⁺ cardiac progenitor cells by inducing apoptosis through FoxO3a activation. These findings will serve as the guide in optimizing the autologous therapy using Sca1⁺ cardiac progenitor cells in cardiac defect babies born exposed to maternal diabetes.

Increased global placental DNA methylation levels are associated with gestational diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes. It is known that GDM is associated with an altered placental function and changes in placental gene regulation. More recent studies demonstrated an involvement of epigenetic mechanisms. So far, the focus regarding placental epigenetic changes in GDM was set on gene-specific DNA methylation analyses. Studies that robustly investigated placental global DNA methylation are lacking. However, several studies showed that tissue-specific alterations in global DNA methylation are independently associated with type 2 diabetes. Thus, the aim of this study was to characterize global placental DNA methylation by robustly measuring placental DNA 5-methylcytosine (5mC) content and to examine whether differences in placental global DNA methylation are associated with GDM.

METHODS

Global DNA methylation was quantified by the current gold standard method, LC-MS/MS. In total, 1030 placental samples were analyzed in this single-center birth cohort study.

RESULTS

Mothers with GDM displayed a significantly increased global placental DNA methylation (3.22 ± 0.63 vs. 3.00 ± 0.46 %; p = 0.013; ±SD). Bivariate logistic regression showed a highly significant positive correlation between global placental DNA methylation and the presence of GDM (p = 0.0009). Quintile stratification according to placental DNA 5mC levels revealed that the frequency of GDM was evenly distributed in quintiles 1-4 (2.9-5.3 %), whereas the frequency in the fifth quintile was significantly higher (10.7 %; p = 0.003). Bivariate logistic models adjusted for maternal age, BMI, ethnicity, recurrent miscarriages, and familiar diabetes predisposition clearly demonstrated an independent association between global placental DNA hypermethylation and GDM. Furthermore, an ANCOVA model considering known predictors of DNA methylation substantiated an independent association between GDM and placental DNA methylation.

CONCLUSIONS

This is the first study that employed a robust quantitative assessment of placental global DNA methylation in over a thousand placental samples. The study provides large scale evidence that placental global DNA hypermethylation is associated with GDM, independent of established risk factors.

Superoxide dismutase 2 overexpression alleviates maternal diabetes-induced neural tube defects, restores mitochondrial function and suppresses cellular stress in diabetic embryopathy

Pregestational diabetes disrupts neurulation leading to neural tube defects (NTDs). Oxidative stress resulting from reactive oxygen species (ROS) plays a central role in the induction of NTD formation in diabetic pregnancies. We aimed to determine whether mitochondrial dysfunction increases ROS production leading to oxidative stress and diabetic embryopathy. Overexpression of the mitochondrion-specific antioxidant enzyme superoxide dismutase 2 (SOD2) in a transgenic (Tg) mouse model significantly reduced maternal diabetes-induced NTDs. SOD2 overexpression abrogated maternal diabetes-induced mitochondrial dysfunction by inhibiting mitochondrial translocation of the pro-apoptotic Bcl-2 family members, reducing the number of defective mitochondria in neuroepithelial cells, and decreasing mitochondrial membrane potential. Furthermore, SOD2 overexpression blocked maternal diabetes-increased ROS production by diminishing dihydroethidium staining signals in the developing neuroepithelium, and reducing the levels of nitrotyrosine-modified proteins and lipid hydroperoxide level in neurulation stage embryos. SOD2 overexpression also abolished maternal diabetes-induced endoplasmic reticulum stress. Finally, caspase-dependent neuroepithelial cell apoptosis enhanced by oxidative stress was significantly reduced by SOD2 overexpression. Thus, our findings support the hypothesis that mitochondrial dysfunction in the developing neuroepithelium enhances ROS production, which leads to oxidative stress and endoplasmic reticulum (ER) stress. SOD2 overexpression blocks maternal diabetes-induced oxidative stress and ER stress, and reduces the incidence of NTDs in embryos exposed to maternal diabetes.