Publications by authors named "Jamie M Pennington"
Article Synopsis
- - Recent studies highlight the need to understand how chemical and non-chemical stressors, like pollution and inflammation, affect public health, particularly regarding lung toxicity from inhaled pollutants such as polycyclic aromatic hydrocarbons (PAHs).
- - In this research, primary human bronchial epithelial cells (HBEC) were cultivated to study the effects of inflammation induced by IL-13 on the toxicity of the pollutant benzo[a]pyrene (BAP), revealing that inflamed cells had poorer barrier integrity and more significant inflammatory responses.
- - RNA sequencing indicated that IL-13-treated HBEC might have a higher risk of uncontrolled cell growth and a diminished immune response following exposure to BAP, providing new insights into how environmental factors
Article Synopsis
- Evaluating the hazards of environmental chemical mixtures, specifically polycyclic aromatic hydrocarbons (PAHs), is a major challenge in human health risk assessment, especially regarding their effects on lung cells.* -
- The study created two synthetic PAH mixtures based on samples from a legacy creosote site and tested their impact on human bronchial epithelial cells, focusing on various toxicological biomarkers.* -
- Results indicated that existing models underestimated toxicity and suggested that PAH interactions might be non-additive, highlighting the need for improved methods in assessing mixture toxicity in environmental samples.*
Article Synopsis
- Current risk assessments for environmental carcinogens often rely on animal studies with doses much higher than what humans actually encounter, leading to uncertainties in evaluating risks.
- This study utilized accelerated mass spectrometry to analyze how a specific carcinogen, benzo[a]pyrene (BaP), behaves in the human body when taken alone or alongside another compound, phenanthrene (Phe), noting significant changes in absorption and distribution.
- The findings suggest that Phe interferes with the absorption of BaP, indicating that the presence of other chemicals in the environment can significantly influence how carcinogens affect human health, which hasn't been thoroughly studied before.
Article Synopsis
- The study investigates the effect of Brussels sprouts (BS) and 3,3'-diindolylmethane (DIM) on the metabolism of a known carcinogen, [C]-benzo[a]pyrene (BaP), using ultra-performance liquid chromatography-accelerator mass spectrometry (UPLC-AMS).
- Volunteers who consumed BS or DIM for a week had lower plasma levels of [C]-BaP and its metabolites after oral micro-dosing, with reductions indicating slower absorption and potentially enhanced clearance.
- This preliminary research suggests that dietary interventions can influence the toxicokinetics of carcinogens in humans, marking a significant step in understanding how diet may affect cancer risk.
Article Synopsis
- * A study investigated the uptake, metabolism, and elimination of carbon-labeled BaP in human plasma using 25 to 250 ng doses over time, showcasing significant inter-individual variability in how BaP is processed in the body.
- * Results indicated that after oral dosing, only about 3-6% of BaP remained as the parent compound in plasma due to extensive metabolism, with non-compartmental modeling revealing a dose-dependent increase in volume distribution and a predominance of
Article Synopsis
- The polyphenol xanthohumol (XN) improves glucose and lipid metabolism in animals with diet-induced obesity, and its effects are believed to depend on the gut microbiota.
- A study tested XN on conventional and germ-free mice with different diets, revealing that XN reduces insulin levels and improves insulin resistance in conventional mice but has no effect in germ-free mice.
- XN alters gut microbiota composition and is metabolized into bioactive compounds, indicating that the intestinal microbiota plays a crucial role in XN's benefits, prompting further research into its complex interactions with diet and host.
Article Synopsis
- 3,3'-Diindolylmethane (DIM) is a compound found in cruciferous vegetables that has potential cancer-preventive properties and is used as a dietary supplement.
- A study involving seven participants showed that after taking DIM capsules for a week, not only parent DIM but also several metabolites were detected in their plasma and urine, which contrasts with previous findings that only identified the parent compound.
- One of the metabolites, identified as 3-((1-indole-3-yl)methyl)indolin-2-one, showed increased effectiveness as an aryl hydrocarbon receptor agonist, suggesting that DIM's metabolites may also have significant biological activity that requires further investigation.
The diet represents one environmental risk factor controlling the progression of type 1 diabetes (T1D) in genetically susceptible individuals. Consequently, understanding which specific nutritional components promote or prevent the development of disease could be used to make dietary recommendations in prediabetic individuals. In the current study, we hypothesized that the immunoregulatory phytochemcial, indole-3-carbinol (I3C) which is found in cruciferous vegetables, will regulate the progression of T1D in nonobese diabetic (NOD) mice.
View Article and Find Full Text PDFFICZ and TCDD, two high-affinity AhR ligands, are reported to have opposite effects on T cell differentiation with TCDD inducing regulatory T cells and FICZ inducing Th17 cells. This dichotomy has been attributed to ligand-intrinsic differences in AhR activation, although differences in sensitivity to metabolism complicate the issue. TCDD is resistant to AhR-induced metabolism and produces sustained AhR activation following a single dose in the μg/kg range, whereas FICZ is rapidly metabolized and AhR activation is transient.
View Article and Find Full Text PDFActivation of the aryl hydrocarbon receptor (AhR) by immunosuppressive ligands promotes the development of regulatory T (Treg) cells. Although AhR-induced Foxp3 Treg cells have been well studied, much less is known about the development and fate of AhR-induced Type 1 Treg (AhR-Tr1) cells. In the current study, we identified the unique transcriptional and functional changes in murine CD4 T cells that accompany the differentiation of AhR-Tr1 cells during the CD4 T-cell-dependent phase of an allospecific cytotoxic T lymphocyte (allo-CTL) response.
View Article and Find Full Text PDFAryl hydrocarbon receptor (AhR) activation by high-affinity ligands mediates immunosuppression in association with increased regulatory T cells (Tregs), making this transcription factor an attractive therapeutic target for autoimmune diseases. We recently discovered 10-chloro-7H-benzimidazo[2,1-a]benzo[de]iso-quinolin-7-one (10-Cl-BBQ), a nanomolar affinity AhR ligand with immunosuppressive activity and favorable pharmacologic properties. In this study, we tested the consequences of AhR activation in the NOD model.
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