Chlormequat chloride is a plant growth regulator whose use on grain crops is on the rise in North America. Toxicological studies suggest that exposure to chlormequat can reduce fertility and harm the developing fetus at doses lower than those used by regulatory agencies to set allowable daily intake levels. Here we report, the presence of chlormequat in urine samples collected from people in the U.S., with detection frequencies of 69%, 74%, and 90% for samples collected in 2017, 2018-2022, and 2023, respectively. Chlormequat was detected at low concentrations in samples from 2017 through 2022, with a significant increase in concentrations for samples from 2023. We also observed high detection frequencies of chlormequat in oat-based foods. These findings and chlormequat toxicity data raise concerns about current exposure levels, and warrant more expansive toxicity testing, food monitoring, and epidemiological studies to assess health effects of chlormequat exposures in humans.ImpactThis study reports the detection of chlormequat, an agricultural chemical with developmental and reproductive toxicity, in the U.S. population and U.S. food supplies for the first time. While similar levels of the chemical were found in urine sampled from 2017 to 2022, markedly increased levels were found in samples from 2023. This work highlights the need for more expansive monitoring of chlormequat in U.S. foods and in human specimens, as well as toxicological and epidemiological study on chlormequat, as this chemical is an emerging contaminant with documented evidence of low-dose adverse health effects in animal studies.
Marine mammals are integral to global biodiversity and marine health through their roles in coastal, benthic, and pelagic ecosystems. Marine mammals face escalating threats from climate change, pollution, and human activities, which perturb their oceanic environment. The diverse biology and extreme adaptations evolved by marine mammals make them important study subjects for understanding anthropogenic pressures on marine ecosystems. However, ethical and logistical constraints restrict the tractability of experimental research with live marine mammals. Additionally, studies on the effects of changing ocean environments are further complicated by intricate gene-environment interactions across populations and species. These obstacles can be overcome with a comprehensive strategy that involves a systems-level approach integrating genotype to phenotype using rigorously defined experimental conditions in vitro and ex vivo. A thorough analysis of the interactions between the genetics of marine mammals and their exposure to anthropogenic pressures will enable robust predictions about how global environmental changes will affect their health and populations. In this perspective, we discuss four challenges of implementing such non-invasive approaches across scientific fields and international borders: 1) practical and ethical limitations of in vivo experimentation with marine mammals, 2) accessibility to relevant tissue samples and cell cultures; 3) open access to harmonized methods and datasets and 4) ethical and equitable research practices. Successful implementation of the proposed approach has the potential impact to inspire new solutions and strategies for marine conservation.
Supplementary Table 2 from Genome-Wide Analysis of the Homeobox C6 Transcriptional Network in Prostate Cancer
Supplemental Figure 3 Figure S3. Low power H&E images of wild-type, PTEN-/-, and PTEN-/-/SOX4-/- prostates.
Supplementary Table 3 from Genome-Wide Analysis of the Homeobox C6 Transcriptional Network in Prostate Cancer
Supplementary Table 4 from Genome-Wide Analysis of the Homeobox C6 Transcriptional Network in Prostate Cancer
Supplemental Figure 1 Figure S1. Breeding scheme for generation of prostate epithelium-specific Sox4 and Pten conditional double-knockout mice. Male PSA-CRE-ER/PTENfl/fl mice (1) were crossed with female Sox4fl/fl mice (2) and bred to homozygosity.
Thousands of known sensory input signals not only govern survival day-to-day and through the seasons but predispose the developing young to improved chances of survival in future anticipated "feast or famine" environmental conditions and to generations beyond. However, what increasingly governs us is not "what nature demands" but biologically confusing, unnatural signals from synthetic chemicals that are made in bulk, paradoxically and sophomorically to "make life better." This review focuses on the role of a subset of endocrine-disrupting chemicals called "metabolism-disrupting chemicals" (MDCs) that alter normal endocrine supervision of metabolism, energy balance and appetite, including the handling and responsiveness to glucose and oxidative stress, and the metabolism of fatty and amino acids. Many known MDCs are petrochemicals and pharmaceuticals (e.g., pesticides, plastics, medicinals, personal care and waste products, etc.). Evidence for the impact of MDCs has gone virtually unabated with unprecedented increases in metabolic diseases, including pathological weight gain, obesity, type II diabetes, metabolic syndrome, nonalcoholic fatty liver disease, Alzheimer's disease, and Parkinson's disease. This is not an exhaustive review of known MDCs, integrated metabolic systems and metabolic diseases, but will highlight examples of each, reference high quality reviews and entertain alternate perspectives with the aim of providing an appreciation for the scope of this problem as it relates to the human health condition.
Supplementary Table 5 from Genome-Wide Analysis of the Homeobox C6 Transcriptional Network in Prostate Cancer
Supplementary Figure 1 from Genome-Wide Analysis of the Homeobox C6 Transcriptional Network in Prostate Cancer
Supplemental Figure 2 Figure S2. Probasin-Cre mice (3) obtained from the NCI mouse repository were crossed to ROSA-lox-stop-lox-GFP mice (C57/BL6;129-ROSA26-Lox-Stop-Lox-EGFP (Charles River Laboratories)). Tissues were harvested from male mice after reaching sexual maturity at 8 weeks of age. GFP imaging of organs was performed on an Olympus OV-100 In Vivo Imaging System. Representative tissues from double transgenic mice are shown on the left, and from control mice on the right. Strong GFP signal was detected in pancreas and all three lobes of the prostate.
Atrial natriuretic peptide (ANP) and its receptors natriuretic peptide receptor (NPR)-A and NPR-C are all highly expressed in alveolar epithelial type II cells (AEC2s) in the late-gestation ovine fetal lung and are dramatically decreased postnatally. However, of all the components, NPR-C stimulation inhibits ANP-mediated surfactant secretion. Since alveolar oxygen increases dramatically after birth, and steroids are administered to mothers antenatally to enhance surfactant lung maturity, we investigated the effects of O2 concentration and steroids on NPR-C-mediated surfactant secretion in AEC2s. NPR-C expression was highest at 5% O2 while being suppressed by 21% O2, in cultured mouse lung epithelial cells (MLE-15s) and/or human primary AEC2s. Surfactant protein-B (SP-B) was significantly elevated in media from both in vitro and ex vivo culture at 13% O2 versus 21% O2 in the presence of ANP or terbutaline (TER). Both ANP and C-ANP (an NPR-C agonist) attenuated TER-induced SP-B secretion; this effect was reversed by dexamethasone (DEX) pretreatment in AEC2s and by transfection with NPR-C siRNA in MLE-15 cells. DEX markedly reduced AEC2 NPR-C expression, and pregnant ewes treated with betamethasone showed reduced ANP in fetal sheep lung fluid. These data suggest that elevated O2 downregulates AEC2 NPR-C and that steroid-mediated NPR-C downregulation in neonatal lungs may provide a novel mechanism for their effect on perinatal surfactant production.
BACKGROUND:Idiopathic Pulmonary Fibrosis (IPF) is the most common and progressive form of the interstitial lung diseases, leading most patients to require lung transplants to survive. Despite the relatively well-defined role of the fibroblast in the progression of IPF, it is the alveolar type II epithelial cell (AEC2) that is now considered the initiation site of damage, driver of disease, and the most efficacious therapeutic target for long-term resolution. Based on our previous studies, we hypothesize that altered lactate metabolism in AEC2 plays a pivotal role in IPF development and progression, affecting key cellular and molecular interactions within the pulmonary microenvironment.METHODS:AEC2s isolated from human patient specimens of non-fibrotic and IPF lungs were used for metabolic measurements, lactate dehydrogenase (LDH) analyses and siRNA-mediated knockdown experiments.RESULTS:AEC2s isolated from human IPF lung explant tissues had lower rates of oxidative metabolism and were more glycolytic lactate-producing cells than were AEC2 from control, non-fibrotic lung explant tissues. Consistent with this shift in metabolism, patient-derived IPF AEC2s exhibited LDH tetramers that have higher ratios of LDHA:LDHB (i.e., favoring pyruvate to lactate conversion) than control AEC2s. Experimental manipulation of LDHA subunit expression in IPF AEC2s restored the bioenergetic profile characteristic of AEC2 from non-fibrotic lungs.CONCLUSIONS:These results are consistent with the concept that altered lactate metabolism may be an underlying feature of AEC2 dysfunction in IPF and may be a novel and important target for therapeutic treatment.
The RNA interference (RNAi) machinery is an essential component of the cell, regulating miRNA biogenesis and function. RNAi complexes were thought to localize either in the nucleus, such as the microprocessor, or in the cytoplasm, such as the RNA-induced silencing complex (RISC). We recently revealed that the core microprocessor components DROSHA and DGCR8, as well as the main components of RISC, including Ago2, also associate with the apical adherens junctions of well-differentiated cultured epithelial cells. Here, we demonstrate that the localization of the core RNAi components is specific and predominant at apical areas of cell-cell contact of human normal colon epithelial tissues and normal primary colon epithelial cells. Importantly, the apical junctional localization of RNAi proteins is disrupted or lost in human colon tumors and in poorly differentiated colon cancer cell lines, correlating with the dysregulation of the adherens junction component PLEKHA7. We show that the restoration of PLEKHA7 expression at adherens junctions of aggressively tumorigenic colon cancer cells restores the junctional localization of RNAi components and suppresses cancer cell growth in vitro and in vivo. In summary, this work identifies the apical junctional localization of the RNAi machinery as a key feature of the differentiated colonic epithelium, with a putative tumor suppressing function.
Mitigating inflammation is clearly important in cancer prevention and control. Traditionally, pharmaceuticals have taken the lead in this problem. In an attempt to 'head them off at the pass', this Forum takes a hard look at the concept of 'better living through chemicals' and limiting proinflammatory chemicals entering the body.
During the Deepwater Horizon oil spill, vast quantities of a chemical dispersant Corexit 9500 were applied in remediation efforts. In addition to the acute toxicity, it is essential to evaluate Corexit further with a broader scope of long‐term sublethal endocrine endpoints. The American alligator ( Alligator mississippiensis ) is an excellent organism for such an endeavor. It exhibits temperature‐dependent sex determination, in which egg incubation temperatures during a thermosensitive period (TSP) in embryonic development determine the sex of embryos. Estrogen signals play a critical role in this process. For example, a single exposure to exogenous estrogen during the TSP overrides the effects of temperature and leads to skewed sex ratios. At a concentration of 100 ppm, Corexit significantly induced transcriptional activity of both alligator nuclear estrogen receptors 1 and 2 in vitro in reporter gene assays. To investigate the estrogenic effects of Corexit on gonadal development, alligator eggs were exposed to Corexit at environmentally relevant concentrations (0.25, 2.5 and 25 ppm) before the TSP in ovo. Exposure to Corexit at 0.25 and 25 ppm significantly delayed hatching and growth. Corexit exposure at any treatment level did not affect sex ratios or testicular mRNA abundance as measured at 1‐week post‐hatching, suggesting that the combination of Corexit components did not synergize enough to induce ovarian development in ovo. These results point to a need for further investigations on individual and combined components of Corexit to understand better their long‐term effects on the development and reproductive health of alligators and other coastal aquatic wildlife.
Evidence indicates that obesity can be promoted by chemical ‘obesogens’ that drive adiposity, hunger, inflammation and suppress metabolism. Dioctyl sodium sulfosuccinate (DOSS), a lipid emulsifier and candidate obesogen in vitro , is widely used in processed foods, cosmetics and as stool softener medicines commonly used during pregnancy. In vivo testing of DOSS was performed in a developmental origins of adult obesity model. Pregnant mice were orally administered vehicle control or DOSS at times and doses comparable to stool softener use during human pregnancy. All weaned offspring consumed only standard diet. Adult male but not female offspring of DOSS-treated dams showed significantly increased body mass, overall and visceral fat masses, and decreased bone area. They exhibited significant decreases in plasma adiponectin and increases in leptin, glucose intolerance and hyperinsulinemia. Inflammatory IL-6 was elevated, as was adipose Cox2 and Nox4 gene expressions, which may be associated with promoter DNA methylation changes. Multiple significant phospholipid/sterol lipid increases paralleled profiles from long-term high-fat diet induced obesity in males. Collectively, developmental DOSS exposure leads to increased adult adiposity, inflammation, metabolic disorder and dyslipidemia in offspring fed a standard diet, suggesting that pharmaceutical and other sources of DOSS taken during human pregnancy might contribute to long-term obesity-related health concerns in offspring.
Deepwater Horizon spilled over 200 million gallons of oil into the waters of the Gulf of Mexico in 2010. In an effort to contain the spill, chemical dispersants were applied to minimize the amount of oil reaching coastal shorelines. However, the biological impacts of chemically-dispersed oil are not well characterized, and there is a particular lack of knowledge concerning sublethal long-term effects of exposure. This study examined potential estrogenic effects of CWAF, Corexit 9500-enhanced water-accommodated fraction of oil, by examining its effect on estrogen receptors and sex determination in the American alligator, Alligator mississippiensis. The alligator exhibits temperature-dependent sex determination which is modulated by estrogen signals, and exposure to 17 beta-estradiol (E-2) and estrogenic compounds in ovo during the thermosensitive period of embryonic development can induce ovarian development at a male producing temperature (MPT). CWAF induced transactivation up to 50% of the maximum induction by E2 via alligator estrogen receptors in vitro. To determine potential endocrine-disrupting effects of exposure directly on the gonad, gonad-adrenal-mesonephric (GAM) organ complexes were isolated from embryos one day prior to the thermosensitive period and exposed to E-2, CWAF, or medium alone in vitro for 8-16 days at MPT. Both CWAF and E-2 exposure induced a significant increase in female ratios. CWAF exposure suppressed GAM mRNA abundances of anti-Mullerian hormone (AMH), sex determining region Y-box 9, and aromatase, whereas E-2 exposure suppressed AMH and increased Forkhead box protein L2 mRNA abundances in GAM. These results indicate that the observed endocrine-disrupting effects of CWAF are not solely estrogenically mediated, and further investigations are required. (C) 2017 Elsevier Inc. All rights reserved.