Effects of in utero exposure to fluoxetine on the gastrointestinal tract of rat offspring.

Perinatal exposure to selective serotonin reuptake inhibitors (SSRIs) has been shown to disrupt the development of serotonergic signaling pathways in the brain and enteric nervous system. Serotonin (5-hydroxytryptamine; 5-HT) signaling is critical for gastrointestinal homeostasis; changes in 5-HT expression and regulation have been associated with gastrointestinal diseases of motility and inflammation. We tested the hypothesis that perinatal exposure to the SSRI fluoxetine can influence the development of the gastrointestinal tract in exposed offspring. Female nulliparous Wistar rats were given fluoxetine (10 mg/kg) or vehicle control from 2 wk before mating until weaning; small and large intestines of female and male offspring were collected at postnatal days 1, 21 (P1, P21, respectively), and 6 mo of age. In histological preparations, the proportion of serotonergic neurons significantly increased in the colons of both female and male fluoxetine-exposed compared with control offspring at P21, a time point that signifies maximal exposure to fluoxetine. At 6 mo of age, male but not female fluoxetine-exposed offspring had a significant increase in circulating 5-HT, with a significant decrease in transcripts encoding the 5-HT2A receptor and monoamine oxidase as compared with control offspring. Measurement of spatiotemporal mapping of contractile activity of the small and large intestine at 6 mo of age revealed no changes in motility in the small bowel of fluoxetine-exposed offspring but revealed a significant increase in the frequency of colonic contractions in the female fluoxetine-exposed compared with control animals. Susceptibility to inflammation was examined at 6 mo using the dextran sulfate sodium model of acute colitis. In utero exposure to fluoxetine was not found to exacerbate colitis severity. These findings suggest that fluoxetine exposure during fetal and early postnatal development can lead to changes in serotonergic neurons at the peak of exposure with sex-specific changes in 5-HT signaling and colonic motility in adulthood.NEW & NOTEWORTHY There is increasing recognition of the relevance of in utero and early postnatal exposures in the developmental programming of the gastrointestinal tract. Perinatal exposure to selective serotonin reuptake inhibitors and antidepressant medications is of particular relevance as they are commonly prescribed during pregnancy, and serotonergic pathways play key roles during gastrointestinal development and in postnatal homeostasis. Here, we provide a comprehensive evaluation of clinically relevant outcomes of gastrointestinal motility and susceptibility to colitis in fluoxetine-exposed offspring and highlight changes in colonic serotonergic neurons at the peak of perinatal fluoxetine exposure with sex-dependent changes in serotonin signaling and colonic motility in adulthood.

Effects of dibenzothiophene, a sulfur-containing heterocyclic aromatic hydrocarbon, and its alkylated congener, 2,4,7-trimethyldibenzothiophene, on placental trophoblast cell function.

Worldwide demand for petroleum products has resulted in increased oil and gas activities in many countries. Conventional and unconventional oil and gas extraction, production, and transport lead to increased levels of petroleum-derived polycyclic aromatic hydrocarbons (PAHs) in the environment. PAH exposure has profound effects on reproduction by affecting pathways involved in placental trophoblast cell function and impairing normal placental development and function-key contributors to reproductive success. However, other components found in petroleum and wastewaters from oil and gas extraction, including the sulfur-containing heterocyclic aromatic compounds such as dibenzothiophene (DBT) and its alkylated derivatives, may also impact reproductive success. The goal of this study was to examine the effect of exposure to DBT, a compound commonly detected in the environment, and one of its alkylated analogues, 2,4,7-trimethyldibenzothiophene (2,4,7-DBT), on steroidogenic and angiogenic pathways critical for mammalian development in placental trophoblast cells (HTR-8/SVneo cells). 2,4,7-DBT but not DBT increased estradiol output in association with increased tube-like formation (surrogate for angiogenesis). These changes in angiogenesis did not appear to be related to altered expression of the key placental angiogenic gene targets (ANGPTL4, VEGFA, and PGF). Neither compound showed a concentration related effect on progesterone synthesis or its receptor expression. Our results suggest that 2,4,7-DBT can disrupt key pathways important for placental trophoblast function and highlight the importance of determining the impact of exposure to both parent and alkylated compounds. Further, these data suggest that exposure to sulfur-containing heterocyclic aromatic compounds may lead to placental dysfunction and impact reproductive success at environmentally relevant levels.

Synthesis of α-methylstilbenes using an aqueous Wittig methodology and application toward the development of potent human aromatase inhibitors.

The development of aqueous Wittig methodology for the synthesis of α-methylstilbenes using tripropylphosphine-derived phosphonium salts is described. The Wittig olefination reaction was high yielding and allowed isolation of stilbenes by simple filtration and washing with water. The novel phosphonium salts employed were accessed via a highly efficient, regioselective addition of hydrogen bromide to styrenes. Application of the α-methylstilbenes toward the synthesis of a collection of stilbenoid-triazoles is reported and their inhibition of CYP450 19A1 (aromatase) investigated. The overall structure-activity profile provided additional evidence on the aryl halide-ketone bioisostere hypothesis and identified 6c as a potent inhibitor of aromatase in vitro (Ki = 8 nM).

Transformative learning for a sustainable and healthy future through ecosystem approaches to health: insights from 15 years of co-designed ecohealth teaching and learning experiences.

This paper presents insights from the work of the Canadian Community of Practice in Ecosystem Approaches to Health (CoPEH-Canada) and 15 years (2008-2022) of land-based, transdisciplinary, learner-centred, transformative learning and training. We have oriented our learning approaches to Head, Hands, and Heart, which symbolise cognitive, psychomotor, and affective learning, respectively. Psychomotor and affective learning are necessary to grapple with and enact far-reaching structural changes (eg, decolonisation) needed to rekindle healthier, reciprocal relationships with nature and each other. We acknowledge that these approaches have been long understood by Indigenous colleagues and communities. We have developed a suite of teaching techniques and resources through an iterative and evolving pedagogy based on participatory approaches and operating reciprocal, research-pedagogical cycles; integrated different approaches and ways of knowing into our pedagogy; and built a networked Community of Practice for continued learning. Planetary health has become a dominant framing for health-ecosystem interactions. This Viewpoint underscores the depth of existing scholarship, collaboration, and pedagogical expertise in ecohealth teaching and learning that can inform planetary health education approaches.

Prenatal nicotine exposure leads to decreased histone H3 lysine 9 (H3K9) methylation and increased p66shc expression in the neonatal pancreas.

Prenatal exposure to nicotine, tobacco's major addictive constituent, has been shown to reduce birth weight and increases apoptosis, oxidative stress, and mitochondrial dysfunction in the postnatal pancreas. Given that upregulated levels of the pro-oxidative adapter protein p66shc is observed in growth-restricted offspring and is linked to beta-cell apoptosis, the goal of this study was to investigate whether alterations in p66shc expression underlie the pancreatic deficits in nicotine-exposed offspring. Maternal administration of nicotine in rats increased p66shc expression in the neonatal pancreas. Similarly, nicotine treatment augmented p66shc expression in INS-1E pancreatic beta cells. Increased p66shc expression was also associated with decreased histone H3 lysine 9 methylation. Finally, nicotine increased the expression of Kdm4c, a key histone lysine demethylase, and decreased Suv39h1, a critical histone lysine methyltransferase. Collectively, these results suggest that upregulation of p66shc through posttranslational histone modifications may underlie the reported adverse outcomes of nicotine exposure on pancreatic function.

The effects of a technical mixture of naphthenic acids on placental trophoblast cell function.

There is considerable concern that naphthenic acids (NA) related to oil extraction can negatively impact reproduction in mammals, yet the mechanisms are unknown. Since placental dysfunction is central to many adverse pregnancy outcomes, the goal of this study was to determine the effects of NA exposure on placental trophoblast cell function. HTR-8/SVneo cells were exposed to a commercial technical NA mixture for 24 hours to assess transcriptional regulation of placentation-related pathways and functional assessment of migration, invasion, and angiogenesis. Pathway analysis suggests that NA treatment resulted in increased epithelial-to-mesenchymal transition. However, there was reduced migration and invasive potential. NA treatment increased angiogenesis-related pathways with a concomitant increase in tube formation. Since decreased trophoblast invasion/migration and aberrant angiogenesis have been associated with placental dysfunction, these findings suggest that it is biologically plausible that exposure to NA may result in altered placental development and/or function.

Δ9-Tetrahydrocannabinol leads to endoplasmic reticulum stress and mitochondrial dysfunction in human BeWo trophoblasts.

While studies have demonstrated that the main psychoactive component of cannabis, Δ9-tetrahydrocannabinol (Δ9-THC) alone induces placental insufficiency and fetal growth restriction, the underlying mechanisms remain elusive. Given that both (i) endoplasmic reticulum (ER) stress in pregnancy and (ii) gestational exposure to Δ9-THC leads to placental deficiency, we hypothesized that Δ9-THC may directly induce placental ER stress, influencing trophoblast gene expression and mitochondrial function. BeWo human trophoblast cells treated with Δ9-THC (3-30 µM) led to a dose-dependent increase in all ER stress markers and CHOP; these effects could be blocked with CB1R/CB2R antagonists. Moreover, expression of ER stress-sensitive genes ERRγ, VEGFA, and FLT-1 were increased by Δ9-THC, and abrogated with the ER stress inhibitor TUDCA. Δ9-THC also diminished mitochondrial respiration and ATP-coupling due to decreased abundance of mitochondrial chain complex proteins. Collectively, these findings indicate that Δ9-THC can directly augment ER stress resulting in aberrant placental gene expression and impaired mitochondrial function.

Adverse effects of naphthenic acids on reproductive health: A focus on placental trophoblast cells.

There is considerable concern that naphthenic acids (NA) related to oil extraction can negatively impact reproduction in mammals yet the mechanisms are unknown. Since placental dysfunction is central to many adverse pregnancy outcomes, the goal of this study was to determine the effects of NA exposure on placental trophoblast cell function. Htr-8/SVneo cells were exposed to a commercial technical NA mixture (Sigma-Aldrich) for 24 h to assess steroid production, markers of inflammation and oxidative stress. NA treatment significantly altered steroid production; progesterone was decreased at all doses tested, whereas there was a significant increase in testosterone production (125 mg/L only). There were no effects on estradiol production. In addition, NA treatment resulted in increased markers of inflammation (interleukin 1ß and prostaglandin E2) and oxidative damage to lipids and nucleic acids. These findings suggest that it is biologically plausible that NA exposure may contribute to placental dysfunction.

The effects of electronic cigarette vapor on placental trophoblast cell function.

Despite evidence that maternal smoking is associated with numerous adverse outcomes, 10-35% of women still smoke during pregnancy. Recently, many smokers have turned to electronic cigarettes (e-cigarettes) as a smoking cessation tool. However, there is considerable uncertainty regarding their safety for use during pregnancy. The goal of this study was to examine the effects of e-cigarette vapour on placental trophoblast function. HTR-8/SVneo cells were exposed to unflavored e-cigarette vapour-conditioned media with and without nicotine to assess cell viability, proliferation, migration (wound healing assay), invasion (transwell extracellular matrix invasion assay), and tube formation, a surrogate for angiogenesis. While there was no effect on cell viability, proliferation or migration (all p > 0.05), e-cigarette conditioned media significantly reduced trophoblast invasion and tube formation; these effects could not be solely attributed to the presence of nicotine. These results suggest that an evaluation of the safety of e-cigarette use during pregnancy is urgently required.