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5 fluorouracil (5FU), an antineoplastic drug, is often utilized in the therapeutic regimen for several types of cancer, including the hepatoblastoma in children. The effects of 5FU on the population of ovarian preantral follicles, which is the largest oocyte reservoir, is still poorly understood. The integrity of the ovarian preantral follicle pool is important for lifelong fertility. The better understanding of such effects may favor intervention strategies to protect fertility in 5FU-treated children and women coping with cancer. To analyze the effects of 5FU on isolated murine secondary follicles in vitro, ovaries were collected from young mice (28-30 days old), and secondary follicles were isolated and cultured for 12 days in basic culture medium, with or without 5FU at concentrations of 0.3 mM, 1 mM, 3 mM, 10 mM, and 30 mM. In the in vitro study, we analyzed the percentage of morphologically normal follicles, antrum formation, follicular diameter, and hormone production. On day 12, oocytes were recovered for in vitro maturation. 5FU treatment did not alter the percentage of morphologically normal follicles. On day 12, only 1, 10, and 30 mM 5FU significantly reduced the percentage of antrum. From day 4 onwards, 5FU treatments significantly reduced follicle diameter. The meiosis resumption rate was significantly lower in all 5FU treatments. 5FU concentrations ≥3 mM reduced estradiol levels. In conclusion, 5FU does not affect follicular morphology. However, 5FU deleteriously affects follicular growth, estradiol production, and oocyte maturation in isolated ovarian follicles.

Aim: To evaluate the prediction capacity of urinary biomarkers for death in critically ill patients with COVID-19. Methods: This is a prospective study with critically ill patients due to COVID-19 infection. The urinary biomarkers NGAL, KIM-1, MCP-1 and nephrin were quantified on ICU admission. Results: There was 40% of death. Urinary nephrin and MCP-1 had no association with death. Tubular biomarkers (proteinuria, NGAL and KIM-1) were predictors of death and cut-off values of them for death were useful in stratify patients with worse prognosis. In a multivariate cox regression analysis, only NGAL remains associated with a two-mount survival chance. Conclusion: Kidney tubular biomarkers, mostly urinary NGAL, had useful capacity to predict death in critically ill COVID-19 patients.

5-Fluorouracil (5-FU), an anti-cancer drug, has been used for hepatoblastoma (HB) chemotherapy in children, who may have impaired ovarian follicle pool reserve with lasting effects to reproduction. Therefore, this study aimed to investigate 5-FU effects on survival, growth, and morphology of ovarian preantral follicles from C57BL6J young mice. Experiments were carried-out both in vivo and in vitro. Mice were treated with 5-FU injection (450 mg/kg i.p) or saline and sacrificed 3 days after to obtain ovaries for histology and molecular biology. Ovaries for in vitro studies were obtained from unchallenged mice and cultured under basic culture medium (BCM) or BCM plus 5-FU (9.2, 46.1, 92.2 mM). Preantral follicles were classified according to developmental stages, and as normal or degenerated. To assess cell viability, caspase-3 immunostaining was performed. Transcriptional levels for apoptosis (Bax, Bcl2, p53, Bax/Bcl2) and Wnt pathway genes (Wnt2 and Wnt4) were also analyzed. Ultrastructural analyses were carried-out on non-cultured ovaries. In addition, β-catenin immunofluorescence was assessed in mouse ovaries. The percentage of all-types normal follicles was significantly lower after 5-FU challenge. A total loss of secondary normal follicles was found in the 5-FU group. The highest 5-FU concentrations reduced the percentage of cultured normal primordial follicles. Large vacuoles were seen in granulosa cells and ooplasm of preantral follicles by electron microscopy. A significantly higher gene expression for Bax and Bax/Bcl2 ratio was seen after 5-FU treatment. A marked reduction in β-catenin immunolabeling was seen in 5-FU-challenged preantral follicles. In the in vitro experiments, apoptotic and Wnt gene transcriptions were significantly altered. Altogether, our findings suggest that 5-FU can deleteriously affect the ovarian follicle reserve by reducing preantral follicles survival.

Methylmercury (MeHg) intoxication is associated with hypertension, hypercholesterolemia, and atherosclerosis by mechanisms that are not yet fully understood. We investigated the effects of MeHg intoxication in atherosclerosis-prone (ApoE-KO) and resistant C57BL/6 mice. Mice were submitted to carotid stenosis surgery (to induce atherosclerosis faster) and received water or MeHg solution (20 mg/L) for 15 days. Tail plethysmography was performed before and after MeHg exposure. Food and MeHg solution intakes were monitored weekly. On the 15th day, mice were submitted to intravital fluorescence microscopy of mesenteric vasculature to observe in vivo leukocyte rolling and adhesion. Results showed that despite the high hair and liver Hg concentrations in the MeHg group, food and water (or MeHg solution) consumption and liver function marker levels were similar to those in controls. MeHg exposure increased total cholesterol, the atherogenic (non-HDL) fraction and systolic and diastolic blood pressure. MeHg exposure also induced inflammation, as seen by the increased rolling and adhered leukocytes in the mesenteric vasculature. Atherosclerosis lesions were more extensive in the aorta and carotid sites of MeHg-ApoE knockout mice. Surprisingly, MeHg exposure also induced atherosclerosis lesions in C57BL/6 mice, which are resistant to atherosclerosis formation. We concluded that MeHg intoxication might represent a risk for cardiovascular diseases since it accelerates atherogenesis by exacerbating several independent risk factors. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s43188-020-00066-x) contains supplementary material, which is available to authorized users.

Apolipoprotein E (ApoE) is a glycoprotein consisting of 299 amino acids, highly produced in the mammalian ovaries. The main function of the ApoE is to transport cholesterol from the peripheral tissues to be metabolized in the liver. In humans, the ApoE gene is polymorphic, with three alleles in a single chromosome-19 locus: APOE2, APOE3, and APOE4. ApoE has also been implicated in cholesterol transport within ovarian follicles to regulate steroidogenesis. Ovarian thecal and granulosa cell cholesterol uptake requires ApoE either by participating in the lipoprotein-receptor complex or lipid endocytosis. In this review, we summarize ApoE role on mammalian ovarian steroidogenesis and on human fertility and discuss recent findings of ApoE4 as an antagonistic pleiotropy gene under adverse environments.

Dyslipidemia is a chronic non-transmissible condition that has increased due to an unhealthy lifestyle. Statins have been used as the standard treatment to control hyperlipidemia. However, side effects and high costs may be associated with its prolonged treatment, so plants derivatives have been an attractive therapy to overcome these problems. Among the compounds extracted from plants, the p-hydroxycinnamic diesters (HCE), present in carnauba wax (CW), have been found with good pharmacological properties. Therefore, this study aimed to evaluate the potential anti-hypercholesterolemic and possible toxicological effects of HCE in C57BL/6J mice under a high-fat (HF) diet. Male C57BL/6J mice were fed during 60 days under the HF diet and therefore were either treated with HCE (200 and 400 mg/kg) or simvastatin (20 mg/kg) or received saline (controls) by gavage for 30 days under the same diet. HCE treatment was able to reduce serum total cholesterol and LDL levels. Besides, this compound increased liver X receptor (LXR) and but not significantly affected IL-1β and TNF-α liver mRNA transcription activity. In conclusion, HCE treatment was found safe and may attenuate the deleterious effects of dyslipidemia due to chronic feeding with western diets.

This study investigated the acute blockade of endogenous melatonin (MLT) using Luzindole with or without systemic lipopolysaccharide (LPS) challenge and evaluated changes in inflammatory and oxidative stress markers in the mouse jejunum. Luzindole is an MT1/MT2 MLT receptor antagonist. Both receptors occur in the small intestine. Swiss mice were treated with either saline (0.35 mg/kg, ip), Luzindole (0.35 mg/kg, ip), LPS (1.25 mg/kg, ip), or Luzindole+LPS (0.35 and 1.25 mg/kg, ip, respectively). Jejunum samples were evaluated regarding intestinal morphometry, histopathological crypt scoring, and PAS-positive villus goblet cell counting. Inflammatory Iba-1, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, nuclear factor (NF)-kB, myeloperoxidase (MPO), and oxidative stress (NP-SHs, catalase, MDA, nitrate/nitrite) markers were assessed. Mice treated with Luzindole, LPS, and Luzindole+LPS showed villus height shortening. Crypt damage was worse in the LPS group. Luzindole, LPS, and Luzindole+LPS reduced the PAS-goblet cell labeling and increased Iba-1-immunolabelled cells compared to the saline group. Immunoblotting for IL-1β, TNF-α, and NF-kB was greater in the Luzindole group. The LPS-challenged group showed higher MPO activity than the saline and Luzindole groups. Catalase was reduced in the Luzindole and Luzindole+LPS groups compared to saline. The Luzindole group showed an increase in NP-SHs, an effect related to compensatory GSH activity. The acute blockade of endogenous MLT with Luzindole induced early changes in inflammatory markers with altered intestinal morphology. The other non-detectable deleterious effects of Luzindole may be balanced by the unopposed direct action of MLT in immune cells bypassing the MT1/MT2 receptors.

Apolipoprotein E plays a crucial role in cholesterol metabolism. The immunomodulatory functions of the human polymorphic APOE gene have gained particular interest because APOE4, a well-recognized risk factor for late-onset Alzheimer's disease, has also been recently linked to increased risk of COVID-19 infection severity in a large UK biobank study. Although much is known about apoE functions in the nervous system, much less is known about APOE polymorphism effects on malnutrition and enteric infections and the consequences for later development in underprivileged environments. In this review, recent findings are summarized of apoE’s effects on intestinal function in health and disease and the role of APOE4 in protecting against infection and malnutrition in children living in unfavorable settings, where poor sanitation and hygiene prevail, is highlighted. The potential impact of APOE4 on later development also is discussed and gaps in knowledge are identified that need to be addressed to protect children's development under adverse environments.

The metabolic syndrome (MetS) epidemic is a global challenge. Although developing countries (including Brazil, India, and South Africa) present a higher proportion of deaths by cardiovascular diseases than developed countries, most of our knowledge is from these developed countries. Amazonian riverine populations (ARP), as well as other vulnerable populations of the Southern Hemisphere, share low-income and traditional practices, among other features. This large cross-sectional study of ARP (n = 818) shows high prevalence of hypertension (51%) and obesity (23%). MetS was diagnosed in 38% of participants (especially in women and 60–69 years-old individuals) without the influence of ancestry. Only 7–8% of adults had no cardio-metabolic abnormalities related to MetS. Atherogenic dyslipidemia (low HDL-cholesterol) was generally observed, including in individuals without MetS. Still, slight differences were detected between settings with a clear predominance of hypertension in Tucuruí. Hypotheses on possible genetic influence and factors (nutrition transition and environmental pollutants -mercury) are proposed for future studies. Moreover, a roadmap to MetS progression based on the most prevalent components is provided for the development of tailored interventions in the Amazon (initially, individuals would present low HDL-cholesterol levels, later progressing to increased blood pressure characterizing hypertension, and ultimately reaching MetS with obesity). Our alarming results support the need to improve our knowledge on these vulnerable populations.

Ruthenium (Ru) compounds, nitric oxide donors in biological systems, have emerged as a promising therapeutical alternative to conventional drugs in anticancer chemotherapy and as a potential neuroprotective agent, with less cytotoxic effects. This minireview summarizes promising studies with ruthenium complexes and their roles in cancer, neuroinflammation, neurovascular, and neurodegenerative diseases. The up-to-date evidence supports that ruthenium-based compounds have beneficial effects against gliomas, and other types of brain cancers, reduce motor symptoms in models of cerebral ischemia-reperfusion, and may act in the control of nociceptive and inflammatory events, such as seen in early Alzheimer's disease. More studies are needed to fill many current knowledge gaps about the intricate and complex ruthenium biological effects and therapeutic-related mechanisms, stimulating further research. Significance Statement In our minireview, we summarize interesting studies addressing the role of ruthenium compounds on neurological illnesses, focusing on brain cancer, neurovascular and neurodegenerative diseases. No such review is available in the literature.

Background Environmental enteric dysfunction (EED) is thought to increase the risk of micronutrient deficiencies, but few studies adjust for dietary intakes and systemic inflammation. Objective We tested whether EED is associated with micronutrient deficiency risk independent of diet and systemic inflammation, and whether it mediates the relation between intake and micronutrient status. Methods Using data from 1283 children in the MAL-ED (Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health) birth cohort we evaluated the risk of anemia, low retinol, zinc, and ferritin, and high transferrin receptor (TfR) at 15 mo. We characterized gut inflammation and permeability by myeloperoxidase (MPO), neopterin (NEO), and α-1-antitrypsin (AAT) concentrations from asymptomatic fecal samples averaged from 9 to 15 mo, and averaged the lactulose:mannitol ratio z-score (LMZ) at 9 and 15 mo. Nutrient intakes from complementary foods were quantified monthly from 9 to 15 mo and densities were averaged for analyses. α-1-Acid glycoprotein at 15 mo characterized systemic inflammation. Relations between variables were modeled using a Bayesian network. Results A greater risk of anemia was associated with LMZ [1.15 (95% CI: 1.01, 1.31)] and MPO [1.16 (1.01, 1.34)]. A greater risk of low ferritin was associated with AAT [1.19 (1.03, 1.37)] and NEO [1.22 (1.04, 1.44)]. A greater risk of low retinol was associated with LMZ [1.24 (1.08, 1.45)]. However, MPO was associated with a lower risk of high transferrin receptor [0.86 (0.74, 0.98)], NEO with a lower risk of low retinol [0.75 (0.62, 0.89)], and AAT with a lower risk of low plasma zinc [0.83 (0.70, 0.99)]. Greater nutrient intake densities (vitamins A and B6, calcium, protein, and zinc) were negatively associated with EED. Inverse associations between nutrient densities and micronutrient deficiency largely disappeared after adjustment for EED, suggesting that EED mediates these associations. Conclusions EED is independently associated with an increased risk of low ferritin, low retinol, and anemia. Greater nutrient density from complementary foods may reduce EED, and the control of micronutrient deficiencies may require control of EED.

The association between cardiovascular and periodontal diseases is characterized by chronic inflammatory processes, with a high prevalence worldwide and complex genetic-environment interactions. Although apolipoprotein E4 (ApoE4), one of the isoforms coded by a polymorphic APOE gene, has been widely recognized as a risk factor for cardiovascular diseases and as an immunoinflammatory factor, less is known regarding how ApoE4 affects atherosclerosis in periodontitis patients. The aim of this review was to investigate the potential underlying mechanisms related to APOE4 that could increase the risk of periodontal disease and, ultimately, of atherosclerosis. There have only been a few studies addressing apoE polymorphisms in patients with chronic periodontitis. To date, no studies have been performed that have assessed how ApoE4 affects atherosclerotic disease in chronic periodontitis patients. Although clinical studies are warranted, experimental studies have consistently documented the presence of periodontal pathogens, which are usually found in the oral cavity and saliva, in the atherosclerotic plaques of ApoE-deficient mice. In addition, in this review, the potential role of the APOE4 allele as an example of antagonistic pleiotropy during human evolution and its relation to oral health is discussed.

Methylmercury (MeHg) toxicity is a major environmental concern. In the aquatic reservoir, MeHg bioaccumulates along the food chain until it is consumed by riverine populations. There has been much interest in the neurotoxicity of MeHg due to recent environmental disasters. Studies have also addressed the implications of long-term MeHg exposure for humans. The central nervous system is particularly susceptible to the deleterious effects of MeHg, as evidenced by clinical symptoms and histopathological changes in poisoned humans. In vitro and in vivo studies have been crucial in deciphering the molecular mechanisms underlying MeHg-induced neurotoxicity. A collection of cellular and molecular alterations including cytokine release, oxidative stress, mitochondrial dysfunction, Ca2+ and glutamate dyshomeostasis, and cell death mechanisms are important consequences of brain cells exposure to MeHg. The purpose of this review is to organize an overview of the mercury cycle and MeHg poisoning events and to summarize data from cellular, animal, and human studies focusing on MeHg effects in neurons and glial cells. This review proposes an up-to-date compendium that will serve as a starting point for further studies and a consultation reference of published studies.

Mercury (Hg) is one of the most toxic environmental pollutants, especially when methylated, forming methylmercury (MeHg). MeHg affects DNA repair, increases oxidative stress, and predisposes to cancer. MeHg neurotoxicity is well-known, but recently MeHg-associated cardiovascular effects were recognized. This study evaluated circulating lipids, oxidative stress, and genotoxicity after MeHg-chronic exposure (20 mg/L in drinking water) in C57BL/6J wild-type and APOE knockout (ko) mice, the latter, being spontaneously dyslipidemic. Experimental mice were assigned to four groups: non-intoxicated and MeHg-intoxicated wild-type mice and non-intoxicated and MeHg-intoxicated APOE ko mice. Plasma levels of triglycerides, total cholesterol (TC), HDL, and LDL were analyzed. Liver lipid peroxidation and splenic gene expression of xeroderma pigmentosum complementation groups A, C, D, and G (XPA, XPC, XPD, and XPG), X-ray repair cross-complementing protein 1 (XRCC1), and telomerase reverse transcriptase (TERT) were measured. Fur Hg levels confirmed chronic MeHg intoxication. MeHg exposure raises TC levels both in wild-type and APOE ko mice. HDL and LDL-cholesterol levels were increased only in the MeHg-challenged APOE ko mice. MeHg increased liver lipid peroxidation, regardless of the genetic background. Unintoxicated APOE ko mice showed higher expression of TERT than all other groups. APOE deficiency increases XPA expression, regardless of MeHg intoxication. Furthermore, MeHg-intoxicated mice had more cytogenetic abnormalities, effect which was independent of APOE deficiency. More studies are needed to dissect the interactions between circulating lipids, MeHg intoxication, and DNA-repair pathways even at young age, interactions that likely play critical roles in cell senescence and the risk for chronic disorders later in life.

In this book chapter, we revisit laboratory animal modeling in neuroscience under modern vivarium biosecurity barriers, which have been critically important to the reproducibility and reliability of the generated data. However, limitations remain in translating data to human populations living in contaminated environments, where lifelong exposures to various levels of biohazards and chemical pollutants often occur. The majority of human populations in the developing world are still intolerably exposed to enteric pathogens and fecal coliforms (even without leading to overt diarrhea) and may be chronically afflicted with low-grade systemic inflammation, especially early in life, the same time window when dynamic events in brain plasticity happen, but also when the intestinal microbiota matures. Individuals living within a contaminated environment and having a related unhealthy gut microbiota may not achieve optimal brain development and may be more predisposed to neurodegenerative diseases later in life. Animal models are needed that better recapitulate these human living conditions and improve our understanding of the role of microbiota in these neurological conditions.

Background Hepatitis C virus (HCV) infection is responsible for a chronic liver inflammation, which may cause end-stage liver disease and hepatocellular carcinoma. Apolipoprotein E (protein: ApoE, gene: APOE), a key player in cholesterol metabolism, is mainly synthesized in the liver and APOE polymorphisms may influence HCV-induced liver damage. Aim To determine whether APOE alleles affect outcomes in HCV-infected patients with liver cirrhosis following orthotopic liver transplantation (OLT). Methods This was a cohort study in which 179 patients, both genders and aged 34-70 years, were included before or after (up to 10 years follow-up) OLT. Liver injury severity was assessed using different criteria, including METAVIR and models for end-stage liver disease. APOE polymorphisms were analyzed by quantitative real-time polymerase chain reaction. Results The APOE3 allele was the most common (67.3%). In inflammation severity of biopsies from 89 OLT explants and 2 patients in pre-transplant, the degree of severe inflammation (A3F4, 0.0%) was significantly less frequent than in patients with minimal and moderate degree of inflammation (≤ A2F4, 16.2%) P = 0.048, in patients carrying the APOE4 allele when compared to non-APOE4. In addition, a significant difference was also found (≤ A2F4, 64.4% vs A3F4, 0.0%; P = 0.043) and (A1F4, 57.4% vs A3F4, 0.0%; P = 0.024) in APOE4 patients when compared to APOE3 carriers. The fibrosis degree of the liver graft in 8 of 91 patients and the lack of the E4 allele was associated with more moderate fibrosis (F2) (P = 0.006). Conclusion Our results suggest that the E4 allele protects against progression of liver fibrosis and degree of inflammation in HCV-infected patients.

Worldwide environmental tragedies of anthropogenic origin causing massive release of metals and other pollutants have been increasing considerably. These pollution outbreaks affect the ecosystems and impact human health. Among those tragedies, recent large-scale environmental disasters in Brazil strongly affected riverside populations, leading to high-risk exposure to methylmercury (MeHg). MeHg is highly neurotoxic to the developing brain. This toxicant causes neural stem cell dysfunction and neurodevelopmental abnormalities. However, less is known about the effects of MeHg in the postnatal neurogenic niche, which harbors neural stem cells and their progeny, in the adult brain. Therefore, taking in consideration the impact of MeHg in human health it is urgent to clarify possible associations between exposure to mercury, accelerated cognitive decline, and neurodegenerative diseases. In this perspectives paper, we discuss the neurotoxic mechanisms of MeHg on postnatal neurogenesis and the putative implications associated with accelerated brain aging and early-onset cognitive decline in populations highly exposed to this environmental neurotoxicant.

BACKGROUND:Multiple factors constrain the trajectories of child cognitive development, but the drivers that differentiate the trajectories are unknown. We examine how multiple early life experiences differentiate patterns of cognitive development over the first 5 years of life in low-and middle-income settings.METHODS:Cognitive development of 835 children from the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) multisite observational cohort study was assessed at 6, 15, 24 (Bayley Scales of Infant and Toddler Development), and 60 months (Wechsler Preschool and Primary Scale of Intelligence). Markers of socioeconomic status, infection, illness, dietary intake and status, anthropometry, and maternal factors were also assessed. Trajectories of development were determined by latent class-mixed models, and factors associated with class membership were examined by discriminant analysis.RESULTS:Five trajectory groups of cognitive development are described. The variables that best discriminated between trajectories included presence of stimulating and learning resources in the home, emotional or verbal responsivity of caregiver and the safety of the home environment (especially at 24 and 60 months), proportion of days (0–24 months) for which the child had diarrhea, acute lower respiratory infection, fever or vomiting, maternal reasoning ability, mean nutrient densities of zinc and phytate, and total energy from complementary foods (9–24 months).CONCLUSIONS:A supporting and nurturing environment was the variable most strongly differentiating the most and least preferable trajectories of cognitive development. In addition, a higher quality diet promoted cognitive development while prolonged illness was indicative of less favorable patterns of development.