Alteration of syncytiotrophoblast mitochondria function and endothelial nitric oxide synthase expression in the placenta of rural residents

Nitric oxide synthase and its function in animal reproduction: an update

Nitric oxide (NO), a free radical labile gas, is involved in the regulation of various biological functions and physiological processes during animal reproduction. Recently, increasing evidence suggests that the biological role and chemical fate of NO is dependent on dynamic regulation of its biosynthetic enzyme, three distinct nitric oxide synthase (NOS) according to their structure, location and function. The impact of NOS isoforms on reproductive functions need to be timely elucidated. Here, we focus on and the basic background and latest studies on the development, structure, importance inhibitor, location pattern, complex functions. Moreover, we summarize the exactly mechanisms which involved some cell signal pathways in the regulation of NOS with cellular and molecular level in the animal reproduction. Therefore, this growing research area provides the new insight into the important role of NOS male and female reproduction system. It also provides the treatment evidence on targeting NOS of reproductive regulation and diseases.

Effects of prenatal pesticide exposure on the fetal brain and placenta transcriptomes in a rodent model

Organophosphate and pyrethroid pesticides are among the most extensively used insecticides worldwide. Prenatal exposures to both classes of pesticides have been linked to a wide range of neurobehavioral deficits in the offspring. The placenta is a neuroendocrine organ and the crucial regulator of the intrauterine environment; early-life toxicant exposures could impact neurobehavior by disrupting placental processes. Female C57BL/6 J mice were exposed via oral gavage to an organophosphate, chlorpyrifos (CPF) at 5 mg/kg, a pyrethroid, deltamethrin (DM), at 3 mg/kg, or vehicle only control (CTL). Exposure began two weeks before breeding and continued every three days until euthanasia at gestational day 17. The transcriptomes of fetal brain (CTL n = 18, CPF n = 6, DM n = 8) and placenta (CTL n = 19, CPF n = 16, DM n = 12) were obtained through RNA sequencing, and resulting data was evaluated using weighted gene co-expression networks, differential expression, and pathway analyses. Fourteen brain gene co-expression modules were identified; CPF exposure disrupted the module related to ribosome and oxidative phosphorylation, whereas DM disrupted the modules related to extracellular matrix and calcium signaling. In the placenta, network analyses revealed 12 gene co-expression modules. While CPF exposure disrupted modules related to endocytosis, Notch and Mapk signaling, DM exposure dysregulated modules linked to spliceosome, lysosome and Mapk signaling pathways. Overall, in both tissues, CPF exposure impacted oxidative phosphorylation, while DM was linked to genes involved in spliceosome and cell cycle. The transcription factor Max involved in cell proliferation was overexpressed by both pesticides in both tissues. In summary, gestational exposure to two different classes of pesticide can induce similar pathway-level transcriptome changes in the placenta and the brain; further studies should investigate if these changes are linked to neurobehavioral impairments.

Molecular mechanisms of hepatotoxicity induced by compounds occurring in Evodiae Fructus

Evodiae Fructus (EF) is a common herbal medicine with thousands of years of medicinal history in China, which has been demonstrated with many promising pharmacological effects on cancer, cardiovascular diseases and Alzheimer's disease. However, there have been increasing reports of hepatotoxicity associated with EF consumption. Unfortunately, in a long term, many implicit constituents of EF as well as their toxic mechanisms remain poorly understood. Recently, metabolic activation of hepatotoxic compounds of EF to generate reactive metabolites (RMs) has been implicated. Herein, we capture metabolic reactions relevant to hepatotoxicity of these compounds. Initially, catalyzed by the hepatic cytochrome P450 enzymes (CYP450s), the hepatotoxic compounds of EF are oxidized to generate RMs. Subsequently, the highly electrophilic RMs could react with nucleophilic groups contained in biomolecules, such as hepatic proteins, enzymes, and nucleic acids to form conjugates and/or adducts, leading to a sequence of toxicological consequences. In addition, currently proposed biological pathogenesis, including oxidative stress, mitochondrial damage and dysfunction, endoplasmic reticulum (ER) stress, hepatic metabolism disorder, and cell apoptosis are represented. In short, this review updates the knowledge on the pathways of metabolic activation of seven hepatotoxic compounds of EF and provides considerable insights into the relevance of proposed molecular hepatotoxicity mechanisms from a biochemical standpoint, for the purpose of providing a theoretical guideline for the rational application of EF in clinics.

Health Effects of Pesticide Exposure in Latin American and the Caribbean Populations: A Scoping Review

BACKGROUND

Multiple epidemiological studies have shown that exposure to pesticides is associated with adverse health outcomes. However, the literature on pesticide-related health effects in the Latin American and the Caribbean (LAC) region, an area of intensive agricultural and residential pesticide use, is sparse. We conducted a scoping review to describe the current state of research on the health effects of pesticide exposure in LAC populations with the goal of identifying knowledge gaps and research capacity building needs.

METHODS

We searched PubMed and SciELO for epidemiological studies on pesticide exposure and human health in LAC populations published between January 2007 and December 2021. We identified 233 publications from 16 countries that met our inclusion criteria and grouped them by health outcome (genotoxicity, neurobehavioral outcomes, placental outcomes and teratogenicity, cancer, thyroid function, reproductive outcomes, birth outcomes and child growth, and others).

RESULTS

Most published studies were conducted in Brazil (37%, n = 88 ) and Mexico (20%, n = 46 ), were cross-sectional in design (72%, n = 167 ), and focused on farmworkers (45%, n = 105 ) or children (21%, n = 48 ). The most frequently studied health effects included genotoxicity (24%, n = 62 ) and neurobehavioral outcomes (21%, n = 54 ), and organophosphate (OP) pesticides were the most frequently examined (26%, n = 81 ). Forty-seven percent (n = 112 ) of the studies relied only on indirect pesticide exposure assessment methods. Exposure to OP pesticides, carbamates, or to multiple pesticide classes was consistently associated with markers of genotoxicity and adverse neurobehavioral outcomes, particularly among children and farmworkers.

DISCUSSION

Our scoping review provides some evidence that exposure to pesticides may adversely impact the health of LAC populations, but methodological limitations and inconsistencies undermine the strength of the conclusions. It is critical to increase capacity building, integrate research initiatives, and conduct more rigorous epidemiological studies in the region to address these limitations, better inform public health surveillance systems, and maximize the impact of research on public policies. https://doi.org/10.1289/EHP9934.

Residential proximity to pesticide applications in Argentine Patagonia: impact on pregnancy and newborn parameters

Among residents living close to agricultural fields who are potentially exposed to pesticides, pregnant women and their fetuses are of particular concern for their vulnerability to environmental chemicals. In this collaborative multicenter study, we covered a wide distribution of participants in the most important fruit production zone of north Patagonia (Argentina) to investigate whether maternal residential proximity to fruit croplands with intense pesticide applications (rural group -RG-) is associated with pregnancy complications and alterations in their newborn parameters compared to the urban population (urban group -UG-). A total of 776 pregnant women met the inclusion criteria. The percentage of threatened miscarriage was significantly higher in the RG than in the UG. The percentage of miscarriage, threat of premature labor, intrauterine fetal death, preterm premature rupture of membranes, and intrauterine growth retardation were similar in both groups. Newborn anthropometric parameters were corrected by sex and gestational age prior to statistical analysis. Length at birth and head circumference were lower in the RG than in the UG. Birth weight was similar in both groups. The percentage of head circumference less than the 5th percentile and the ponderal index were greater in the RG than in the UG. Our results suggest that proximity to pesticide applications may increase the risk of pregnancy complications and altered newborn parameters.

Silver bionanoparticles toxicity in trophoblast is mediated by nitric oxide and glutathione pathways

Silver bionanoparticles (AgNPs) biosynthesized by Pseudomonas aeruginosa culture supernatant have an important antibacterial activity mediated by ROS increase; however their toxicity in human cells is not known. Due to the high susceptibility of the developing tissues to xenobiotics, the aim of this study was to investigate the AgNPs effect on first trimester human trophoblasts. The HTR8/SVneo cell line was treated with AgNPs (0.3-1.5 pM), for 6 and 24 h. Cell viability, reactive nitrogen and oxygen species (RNS and ROS) production, nitric oxide synthase expression, antioxidant defenses and biomolecule damage were evaluated. The exposure to AgNPs produced changes in HTR8/SVneo cell morphology and decreased cell viability. Alterations in redox balance were observed, with an increase in ROS and RNS levels, and NOS2 protein expression. Superoxide dismutase and catalase augmented their activity accompanied with a decreased in glutathione content and glutathione S-transferase activity. Protein oxidation and genotoxic damage were observed at concentrations greater than 0.6 pM. The pre-incubation with l-NMMA, NAC, mannitol and peroxidase demonstrated that AgNPs-induced cytotoxicity was not mediated by HO and H₂O₂, but nitric oxide and glutathione pathways were implicated in cell death. Since reported AgNPs microbicidal mechanism is mediated by increasing ROS (mainly HO and H₂O₂) without an increase in RNS, this work indicates an interesting difference in the reactive species and oxidative pathways involved in AgNPs toxicity in eukaryotic and prokaryotic cells. Highlighting the importance of toxicity evaluation to determine the safety of AgNPs with pharmaceutical potential uses.

Epigenetic disruption of estrogen receptor alpha is induced by a glyphosate-based herbicide in the preimplantation uterus of rats

Previously, we have shown that perinatal exposure to a glyphosate-based herbicide (GBH) induces implantation failures in rats. Estrogen receptor alpha (ERα) is critical for successful implantation. ERα transcription is under the control of five promoters (E1, OT, O, ON, and OS), which yield different transcripts. Here, we studied whether perinatal exposure to a GBH alters uterine ERα gene expression and prompts epigenetic modifications in its regulatory regions during the preimplantation period. Pregnant rats (F0) were orally treated with 350 mg glyphosate/kg bw/day through food from gestational day (GD) 9 until weaning. F1 females were bred, and uterine samples were collected on GD5 (preimplantation period). ERα mRNA levels and its transcript variants were evaluated by RT-qPCR. Enzyme-specific restriction sites and predicted transcription factors were searched in silico in the ERα promoter regions to assess the methylation status using the methylation-sensitive restriction enzymes-PCR technique. Post-translational modifications of histones were studied by the chromatin immunoprecipitation assay. GBH upregulated the expression of total ERα mRNA by increasing the abundance of the ERα-O transcript variant. In addition, different epigenetic changes were detected in the O promoter. A decrease in DNA methylation was observed in one of the three sites evaluated in the O promoter. Moreover, histone H4 acetylation and histone H3 lysine 9 trimethylation (H3K9me3) were enriched in the O promoter in GBH-exposed rats, whereas H3K27me3 was decreased. All these alterations could account for the increase in ERα gene expression. Our findings show that perinatal exposure to a GBH causes long-term epigenetic disruption of the uterine ERα gene, which could be associated with the GBH-induced implantation failures.

Susceptibility of placental mitochondria to oxidative stress

BACKGROUND

Two different mitochondrial fractions (MFs) have been characterized in the human placenta: the "light" and "heavy" fractions (LMF and HMF). Although these organelles are the main source of reactive oxygen species, an imbalance between their production and the rate of detoxification represents a serious threat to mitochondrial homeostasis and, in the case of the placenta, also to the fetus. The aim of this study was to evaluate the antioxidant capacity and susceptibility to oxidative stress in both types of MFs.

METHODS

Human MFs were isolated from healthy donors (n = 11) and either incubated or not with H₂ O₂ . Catalase (CAT) activity, and reduced glutathione (GSH), lipid peroxidation (LP), and protein carbonylation (PC) levels were determined.

RESULTS

H₂ O₂ treatment increased LP and PC levels and decreased CAT activity. GSH levels were similar in control and treated MFs.

CONCLUSION

H₂ O₂ caused oxidative damage in both LMF and HMF and the antioxidant system measured in these two MFs responded similarly. To the best of our knowledge, this is the first partial description of the antioxidant defense in placental HMF and LMF performed in a cell-free assay. The small number of antioxidant system parameters measured did not allow detecting differences between HMF and LMF.

Molecular Mechanisms Involved in Oxidative Stress-Associated Liver Injury Induced by Chinese Herbal Medicine: An Experimental Evidence-Based Literature Review and Network Pharmacology Study

Oxidative stress, defined as a disequilibrium between pro-oxidants and antioxidants, can result in histopathological lesions with a broad spectrum, ranging from asymptomatic hepatitis to hepatocellular carcinoma in an orchestrated manner. Although cells are equipped with sophisticated strategies to maintain the redox biology under normal conditions, the abundance of redox-sensitive xenobiotics, such as medicinal ingredients originated from herbs or animals, can dramatically invoke oxidative stress. Growing evidence has documented that the hepatotoxicity can be triggered by traditional Chinese medicine (TCM) during treating various diseases. Meanwhile, TCM-dependent hepatic disorder represents a strong correlation with oxidative stress, especially the persistent accumulation of intracellular reactive oxygen species. Of note, since TCM-derived compounds with their modulated targets are greatly diversified among themselves, it is complicated to elaborate the potential pathological mechanism. In this regard, data mining approaches, including network pharmacology and bioinformatics enrichment analysis have been utilized to scientifically disclose the underlying pathogenesis. Herein, top 10 principal TCM-modulated targets for oxidative hepatotoxicity including superoxide dismutases (SOD), malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), glutathione peroxidase (GPx), Bax, caspase-3, Bcl-2, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and nitric oxide (NO) have been identified. Furthermore, hepatic metabolic dysregulation may be the predominant pathological mechanism involved in TCM-induced hepatotoxic impairment.

Neonatal, placental, and umbilical cord blood parameters in pregnant women residing in areas with intensive pesticide application

In rural populations, the proximity to areas with intensive pesticide application represents a risk factor of xenobiotic exposure. Here, we investigated whether newborns born to mothers residing in an area with intensive pesticide application show alterations in placental and neonatal morphometric standards, umbilical cord blood (UCB) biochemical parameters, and/or biomarkers related to oxidative stress and oxidative damage. Samples were collected from 151 healthy pregnant women residing in a rural area (rural group; RG) during the pesticide spraying (SS) and nonspraying (NSS) seasons, as well as from women from an urban population (control group; CG), and grouped according to the delivery type (vaginal or cesarean). In the vaginal delivery group, the placental weight and placental index were higher in the RG groups than in the CG (p = 0.01), whereas in the cesarean delivery group, newborn weight was lower in the RG-SS group than in the CG. In the RG-SS group, UCB erythrocyte osmotic fragility and the DNA damage index (DI) were higher, and superoxide dismutase (SOD) activity was lower than in the RG-NSS group. Acetylcholinesterase and SOD activities were found to be inversely correlated with the DI.