32 results on '"Greathouse KL"'
Search Results
2. Associations Between Dietary Patterns and Quality of Life in a Longitudinal Cohort of Colorectal Cancer Survivors.
- Author
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Smith KS, Gudenkauf LM, Hoogland AI, Li X, Hoobler R, Playdon MC, Gigic B, Small BJ, Gonzalez BD, Oswald LB, Byrd DA, Greathouse KL, Ulrich CM, Li CI, Shibata D, Toriola AT, Peoples AR, Siegel EM, Figueiredo JC, Jim HSL, and Crowder SL
- Subjects
- Humans, Female, Male, Middle Aged, Aged, Longitudinal Studies, Prospective Studies, Adult, Cross-Sectional Studies, Feeding Behavior psychology, United States epidemiology, Dietary Patterns, Quality of Life, Colorectal Neoplasms psychology, Cancer Survivors psychology, Cancer Survivors statistics & numerical data, Diet
- Abstract
Purpose: To characterize dietary patterns and examine associations with cross-sectional and longitudinal changes in quality of life (QOL) over approximately one year after colorectal cancer (CRC) diagnosis., Methods: The ColoCare Study is an international, multi-center, prospective cohort study of newly diagnosed CRC survivors of any stage. A subset of participants with CRC in the United States completed patient-reported outcome measures at 6- and 12-months post-enrollment, including the Food Frequency Questionnaire (FFQ) and European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). Dietary patterns at 6 months (around the time of treatment completion) were identified using Principal Component Analysis (PCA) with varimax rotation. Adherence scores were calculated for participants within each dietary pattern, with higher scores indicating higher adherence. Mixed models were used to examine the effect of each dietary pattern on changes in QOL at 6- and 12-month follow-ups, controlling for cancer stage, biological sex, body mass index (BMI), smoking status, and age., Results: Participants (N = 174) were, on average, 56 ± 14 years old and were mostly female (51.5%), stage III or IV (51.7%), never smokers (60.2%), non-Hispanic (97.1%), and White (83.3%) with a BMI of 27.9 ± 6.1 kg/m
2 . PCA revealed two emerging dietary patterns: "Western diet", characterized by processed meats, refined grains, and sugars, and "Prudent diet" characterized by lean proteins, fruits, and vegetables. Higher adherence to a Western diet was associated with worse social functioning at 6-month follow-up (FE = -12.6, p = 0.010). Loss of appetite from 6 to 12 months was associated with higher adherence to both the Western and Prudent dietary patterns (FE = 1.5, p = 0.044; FE = 1.3, p = 0.046, respectively). Neither dietary pattern was associated with global QOL score at 6- or 12-month follow-up ( p 's > 0.05)., Conclusions: Among CRC survivors in the United States, the Western diet was concurrently associated with worse social functioning. Loss of appetite was reported by CRC survivors following both dietary patterns, suggesting that loss of appetite may be a global experience for CRC survivors during this timeframe. Further research is needed to understand specific social challenges experienced by CRC survivors and develop supportive care interventions to address appetite and nutritional concerns.- Published
- 2024
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3. Acidovorax temperans skews neutrophil maturation and polarizes Th17 cells to promote lung adenocarcinoma development.
- Author
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Stone JK, von Muhlinen N, Zhang C, Robles AI, Flis AL, Vega-Valle E, Miyanaga A, Matsumoto M, Greathouse KL, Cooks T, Trinchieri G, and Harris CC
- Abstract
Change within the intratumoral microbiome is a common feature in lung and other cancers and may influence inflammation and immunity in the tumor microenvironment, affecting growth and metastases. We previously characterized the lung cancer microbiome in patients and identified Acidovorax temperans as enriched in tumors. Here, we instilled A. temperans in an animal model driven by mutant K-ras and Tp53. This revealed A. temperans accelerates tumor development and burden through infiltration of proinflammatory cells. Neutrophils exposed to A. temperans displayed a mature, pro-tumorigenic phenotype with increased cytokine signaling, with a global shift away from IL-1β signaling. Neutrophil to monocyte and macrophage signaling upregulated MHC II to activate CD4
+ T cells, polarizing them to an IL-17A+ phenotype detectable in CD4+ and γδ populations (T17). These T17 cells shared a common gene expression program predictive of poor survival in human LUAD. These data indicate bacterial exposure promotes tumor growth by modulating inflammation., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)- Published
- 2024
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4. Co-enrichment of cancer-associated bacterial taxa is correlated with immune cell infiltrates in esophageal tumor tissue.
- Author
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Greathouse KL, Stone JK, Vargas AJ, Choudhury A, Padgett RN, White JR, Jung A, and Harris CC
- Subjects
- Humans, Case-Control Studies, RNA, Ribosomal, 16S genetics, Fusobacterium genetics, Blood Platelets, Esophageal Neoplasms
- Abstract
Esophageal carcinoma (ESCA) is a leading cause of cancer-related death worldwide, and certain oral and intestinal pathogens have been associated with cancer development and progression. We asked if esophageal microbiomes had shared alterations that could provide novel biomarkers for ESCA risk. We extracted DNA from tumor and non-tumor tissue of 212 patients in the NCI-MD case control study and sequenced the 16S rRNA gene (V3-4), with TCGA ESCA RNA-seq (n = 172) and WGS (n = 123) non-human reads used as validation. We identified four taxa, Campylobacter, Prevotella, Streptococcus, and Fusobacterium as highly enriched in esophageal cancer across all cohorts. Using SparCC, we discovered that Fusobacterium and Prevotella were also co-enriched across all cohorts. We then analyzed immune cell infiltration to determine if these dysbiotic taxa were associated with immune signatures. Using xCell to obtain predicted immune infiltrates, we identified a depletion of megakaryocyte-erythroid progenitor (MEP) cells in tumors with presence of any of the four taxa, along with enrichment of platelets in tumors with Campylobactor or Fusobacterium. Taken together, our results suggest that intratumoral presence of these co-occurring bacterial genera may confer tumor promoting immune alterations that allow disease progression in esophageal cancer., (© 2023. The Author(s).)
- Published
- 2024
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5. A preparation of bacterial outer membrane with osmium tetroxide and uranyl acetate co-stain enables improved structural determination by transmission electron microscopy.
- Author
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Sheikh A, Zechmann B, Sayes CM, Taube JH, and Greathouse KL
- Subjects
- Microscopy, Electron, Bacterial Outer Membrane, Microscopy, Electron, Transmission, Staining and Labeling, Osmium, Coloring Agents, Osmium Tetroxide
- Abstract
Biological nanoparticles, such as bacterial outer membrane vesicles (OMVs), are routinely characterized through transmission electron microscopy (TEM). In this study, we report a novel method to prepare OMVs for TEM imaging. To preserve vesicular shape and structure, we developed a dual fixation protocol involving osmium tetroxide incubation prior to negative staining with uranyl acetate. Combining osmium tetroxide with uranyl acetate resulted in preservation of sub-50 nm vesicles and improved morphological stability, enhancing characterization of lipid-based nanoparticles by TEM., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
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6. Control of Helicobacter pylori with engineered probiotics secreting selective guided antimicrobial peptides.
- Author
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Choudhury A, Ortiz PS, Young M, Mahmud MT, Stoffel RT, Greathouse KL, and Kearney CM
- Abstract
Helicobacter pylori is the primary cause of 78% of gastric cancer cases, providing an opportunity to prevent cancer by controlling a single bacterial pathogen within the complex gastric microbiota. We developed highly selective antimicrobial agents against H. pylori by fusing an H. pylori -binding guide peptide (MM1) to broad-spectrum antimicrobial peptides. The common dairy probiotic Lactococcus lactis was then engineered to secrete these guided antimicrobial peptides (gAMPs). When co-cultured in vitro with H. pylori , the gAMP probiotics lost no toxicity compared to unguided AMP probiotics against the target, H. pylori , while losing >90% of their toxicity against two tested off-target bacteria. To test binding to H. pylori , the MM1 guide was fused to green fluorescent protein (GFP), resulting in enhanced binding compared to unguided GFP as measured by flow cytometry. In contrast, MM1-GFP showed no increased binding over GFP against five different off-target bacteria. These highly selective gAMP probiotics were then tested by oral gavage in mice infected with H. pylori . As a therapy, the probiotics outperformed antibiotic treatment, effectively eliminating H. pylori in just 5 days, and also protected mice from challenge infection as a prophylactic. As expected, the gAMP probiotics were as toxic against H. pylori as the unguided AMP probiotics. However, a strong rebound in gastric species diversity was found with both the selective gAMP probiotics and the non-selective AMP probiotics. Eliminating the extreme microbial dysbiosis caused by H. pylori appeared to be the major factor in diversity recovery. IMPORTANCE Alternatives to antibiotics in the control of Helicobacter pylori and the prevention of gastric cancer are needed. The high prevalence of H. pylori in the human population, the induction of microbial dysbiosis by antibiotics, and increasing antibiotic resistance call for a more sustainable approach. By selectively eliminating the pathogen and retaining the commensal community, H. pylori control may be achieved without adverse health outcomes. Antibiotics are typically used as a therapeutic post-infection, but a more targeted, less disruptive approach could be used as a long-term prophylactic against H. pylori or, by extension, against other gastrointestinal pathogens. Furthermore, the modular nature of the guided antimicrobial peptide (gAMP) technology allows for the substitution of different guides for different pathogens and the use of a cocktail of gAMPs to avoid the development of pathogen resistance.
- Published
- 2023
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7. The intratumor microbiome is associated with microsatellite instability.
- Author
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Byrd DA, Fan W, Greathouse KL, Wu MC, Xie H, and Wang X
- Subjects
- Humans, Microsatellite Instability, Tumor Microenvironment genetics, Colorectal Neoplasms pathology, Stomach Neoplasms genetics, Adenocarcinoma genetics
- Abstract
Intratumoral microbes may have multifunctional roles in carcinogenesis. Microsatellite instability (MSI) is associated with higher tumor immunity and mutational burden. Using whole transcriptome and whole genome sequencing microbial abundance data, we investigated associations of intratumoral microbes with MSI, survival, and MSI-relevant tumor molecular characteristics across multiple cancer types including colorectal cancer (CRC), stomach adenocarcinoma, and endometrial carcinoma. Among 451 CRC patients, our key finding was strong associations of multiple CRC-associated genera, including Dialister and Casatella, with MSI. Dialister and Casatella abundance was associated with improved overall survival (hazard ratiomortality = 0.56, 95% confidence interval = 0.34 to 0.92, and hazard ratiomortality = 0.44, 95% confidence interval = 0.27 to 0.72), respectively, comparing higher relative to lower quantiles. Multiple intratumor microbes were associated with immune genes and tumor mutational burden. Diversity of oral cavity-originating microbes was also associated with MSI among CRC and stomach adenocarcinoma patients. Overall, our findings suggest the intratumor microbiota may differ by MSI status and play a role in influencing the tumor microenvironment., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
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8. Diet-microbiome interactions in cancer treatment: Opportunities and challenges for precision nutrition in cancer.
- Author
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Greathouse KL, Wyatt M, Johnson AJ, Toy EP, Khan JM, Dunn K, Clegg DJ, and Reddy S
- Subjects
- Diet, Humans, Nutritional Status, Gastrointestinal Microbiome physiology, Malnutrition, Microbiota, Neoplasms drug therapy, Neoplasms therapy
- Abstract
Dietary patterns contribute to cancer risk. Separately, microbial factors influence the development of several cancers. However, the interaction of diet and the microbiome and their joint contribution to cancer treatment response needs more research. The microbiome significantly impacts drug metabolism, immune activation, and response to immunotherapy. One of the critical factors affecting the microbiome structure and function is diet. Data demonstrate that the diet and microbiome composition affects the immune response. Moreover, malnutrition is a significant confounder to cancer therapy response. There is little understanding of the interaction of malnutrition with the microbiome in the context of cancer. This review aims to address the current knowledge of dietary intake patterns and malnutrition among cancer patients and the impact on treatment outcomes. Second, this review will provide evidence linking the microbiome to cancer treatment response and provide evidence of the potentially strong effect that diet could have on this interaction. This review will formulate critical questions that will need further research to understand the diet-microbiome relationship in cancer treatment response and directions for future research to guide us to precision nutrition therapy to improve cancer outcomes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Inc.)
- Published
- 2022
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9. Impaired proteostasis in obese skeletal muscle relates to altered immunoproteasome activity.
- Author
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Fletcher E, Wiggs M, Greathouse KL, Morgan G, and Gordon PM
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- Animals, Diet, High-Fat, Inflammation metabolism, Male, Mice, Mice, Inbred C57BL, Muscle, Skeletal metabolism, Obesity metabolism, Sucrose, Proteasome Endopeptidase Complex metabolism, Proteostasis
- Abstract
Obesity-associated inflammation and/or oxidative stress can damage intramuscular proteins and jeopardize muscle integrity. The immunoproteasome (iProt) is vital to remove oxidatively modified proteins, but this function may be compromised with obesity. We sought to elucidate whether diet-induced obesity alters intramuscular iProt content and activity in mice to identify a possible mechanism for impaired muscle proteostasis in the obese state. Total proteasome content and activity and estimates of muscle oxidative damage, inflammation, muscle mass and strength were also assessed. Twenty-three male, 5-week-old C57BL/6J mice were fed a high-fat, high-sucrose (HFS; 45% kcal fat, 17% sucrose, n = 12) or low-fat, low-sucrose (LFS; 10% kcal fat, 0% sucrose, n = 11) diet for 12 weeks. Strength was assessed via a weightlifting test. Despite no change in pro-inflammatory cytokines ( P > 0.05), oxidative protein damage was elevated within the gastrocnemius ( P = 0.036) and tibialis anterior ( P = 0.033) muscles of HFS-fed mice. Intramuscular protein damage coincided with reduced iProt and total proteasome activity ( P < 0.05), and reductions in relative muscle mass ( P < 0.001). Therefore, proteasome dysregulation occurs in obese muscle and may be a critical link in muscle oxidative stress. Novelty: Our results show for the first time that immunoproteasome and total proteasome function is significantly reduced within obese muscle. Visceral fat mass is a significant predictor of diminished proteasome activity in skeletal muscle. Proteasome function is inversely correlated with an intramuscular accumulation of oxidatively damaged proteins.
- Published
- 2022
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10. Exploration of Diet Quality by Obesity Severity in Association with Gestational Weight Gain and Distal Gut Microbiota in Pregnant African American Women: Opportunities for Intervention.
- Author
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Greathouse KL, Padgett RN, Petrosino J, Hastings-Tolsma M, and Faucher MA
- Subjects
- Black or African American, Body Mass Index, Diet, Female, Humans, Obesity, Pregnancy, Prospective Studies, Vegetables, Gastrointestinal Microbiome, Gestational Weight Gain, Pregnancy Complications
- Abstract
Objective: To conduct an exploratory examination of dietary patterns and quality during pregnancy in African-American women who were class I, II, or III obese, and those women with normal pre-pregnancy body mass index (pBMI), as well to identify dietary factors associated with GWG, and changes in the distal gut microbiome. African American women represent the largest group affected by pre-pregnancy obesity, a risk factor for several adverse birth outcomes., Methods: This prospective study investigated the association between diet, distal gut microbiome, and GWG among African-American women (n = 21) with obesity (n = 15) compared to women with a normal pre-pregnancy body mass index (pBMI) (n = 6) at two time points, 27-29 and 37-39 weeks gestation. Dietary patterns associated with obesity severity and GWG gain were assessed using Welch's T-test and Mann-Whitney U. The association between the gut microbiome and dietary patterns was assessed using a regression-based kernel association test and the adaptive microbiome-based sum of powered score test., Results: In early pregnancy, dietary intake of Total Fruits and Greens and Beans was significantly different between pBMI and GWG groups; significance was 0.022 and 0.028 respectively. Women with Class II/III obesity and those with GWG above guidelines had Healthy Eating Index (HEI) scores below 50, meeting less than 75% of dietary guidelines, and did not meet recommendations for fruit and vegetable or fiber intake. We found no significant associations between the microbiome composition and diet (HEI Scores)., Conclusions for Practice: Overall, the results indicate that women with pBMI obesity are not meeting minimum dietary guidelines for nutrient intakes during pregnancy, specifically fruits, vegetables, and fiber, regardless of GWG. Interventions for African-American women with pre-pregnancy obesity, with a focus on increasing consumption of fruits and vegetables, would be beneficial to control GWG and improve birth outcomes., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2022
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11. Spiking immunotherapy with a bacterial cocktail brings T cells back to the fight.
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Greathouse KL and Choudhury A
- Subjects
- Bacteria, Humans, Immunotherapy, T-Lymphocytes, Gastrointestinal Microbiome, Melanoma therapy
- Abstract
A recent study by Montalban-Arques et al.
1 in Cell Host & Microbe shows that augmenting the function of the gut microbiota reduces tumor burden. Four Clostridiales species blocked tumor growth as efficient as chemotherapy or immunotherapy in colorectal cancer and melanoma., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)- Published
- 2021
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12. Contribution of the microbiota and their secretory products to inflammation and colorectal cancer pathogenesis: the role of toll-like receptors.
- Author
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Sheikh A, Taube J, and Greathouse KL
- Subjects
- Colorectal Neoplasms metabolism, Colorectal Neoplasms microbiology, Humans, Colorectal Neoplasms pathology, Gastrointestinal Microbiome, Inflammation metabolism, Toll-Like Receptors metabolism
- Abstract
Alterations in diversity and function of the gut microbiome are associated with concomitant changes in immune response, including chronic inflammation. Chronic inflammation is a major risk factor for colorectal cancer (CRC). An important component of the inflammatory response system are the toll-like receptors (TLRs). TLRs are capable of sensing microbial components, including nucleic acids, lipopolysaccharides and peptidoglycans, as well as bacterial outer membrane vesicles (OMV). OMVs can be decorated with or carry as cargo these TLR activating factors. These microbial factors can either promote tolerance or activate signaling pathways leading to chronic inflammation. Herein we discuss the role of the microbiome and the OMVs that originate from intestinal bacteria in promoting chronic inflammation and the development of colitis-associated CRC. We also discuss the contribution of TLRs in mediating the microbiome-inflammation axis and subsequent cancer development. Understanding the role of the microbiome and its secretory factors in TLR response may lead to the development of better cancer therapeutics., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
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13. Does caloric restriction prime the microbiome for pathogenic bacteria?
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Greathouse KL and Johnson AJ
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- Animals, Clostridioides difficile, Fecal Microbiota Transplantation, Feces microbiology, Germ-Free Life, Humans, Mice, Obesity microbiology, Weight Loss, Bacteria pathogenicity, Caloric Restriction, Gastrointestinal Microbiome
- Abstract
A recent study in Nature finds significant shifts in the gut microbiome of post-menopausal women on severe calorie restriction concomitant with weight loss. Microbiota transplantation to germ-free mice display a similar weight loss, along with a bloom in C. difficile, unlocking clues to microbial metabolic alteration in weight loss., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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14. Phytochemicals as Therapeutic Interventions in Peripheral Artery Disease.
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Ismaeel A, Greathouse KL, Newton N, Miserlis D, Papoutsi E, Smith RS, Eidson JL, Dawson DL, Milner CW, Widmer RJ, Bohannon WT, and Koutakis P
- Subjects
- Animals, Clinical Trials as Topic, Humans, Nutrition Therapy methods, Peripheral Arterial Disease therapy, Phytochemicals therapeutic use
- Abstract
Peripheral artery disease (PAD) affects over 200 million people worldwide, resulting in significant morbidity and mortality, yet treatment options remain limited. Among the manifestations of PAD is a severe functional disability and decline, which is thought to be the result of different pathophysiological mechanisms including oxidative stress, skeletal muscle pathology, and reduced nitric oxide bioavailability. Thus, compounds that target these mechanisms may have a therapeutic effect on walking performance in PAD patients. Phytochemicals produced by plants have been widely studied for their potential health effects and role in various diseases including cardiovascular disease and cancer. In this review, we focus on PAD and discuss the evidence related to the clinical utility of different phytochemicals. We discuss phytochemical research in preclinical models of PAD, and we highlight the results of the available clinical trials that have assessed the effects of these compounds on PAD patient functional outcomes.
- Published
- 2021
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15. Targeting Dietary and Microbial Tryptophan-Indole Metabolism as Therapeutic Approaches to Colon Cancer.
- Author
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Wyatt M and Greathouse KL
- Subjects
- Basic Helix-Loop-Helix Transcription Factors antagonists & inhibitors, Basic Helix-Loop-Helix Transcription Factors metabolism, Carcinogenesis drug effects, Carcinogenesis immunology, Colon microbiology, Colon pathology, Colonic Neoplasms immunology, Colonic Neoplasms metabolism, Colonic Neoplasms microbiology, Combined Modality Therapy methods, Enzyme Inhibitors pharmacology, Enzyme Inhibitors therapeutic use, Gastrointestinal Microbiome immunology, Host Microbial Interactions immunology, Humans, Indoleamine-Pyrrole 2,3,-Dioxygenase antagonists & inhibitors, Indoleamine-Pyrrole 2,3,-Dioxygenase metabolism, Indoles administration & dosage, Indoles metabolism, Intestinal Mucosa immunology, Intestinal Mucosa microbiology, Intestinal Mucosa pathology, Kynurenine metabolism, Metabolic Networks and Pathways drug effects, Metabolic Networks and Pathways immunology, Probiotics administration & dosage, Proto-Oncogene Proteins c-myc antagonists & inhibitors, Proto-Oncogene Proteins c-myc metabolism, Receptors, Aryl Hydrocarbon antagonists & inhibitors, Receptors, Aryl Hydrocarbon metabolism, Symbiosis immunology, Tumor Microenvironment drug effects, Tumor Microenvironment immunology, Carcinogenesis metabolism, Colonic Neoplasms therapy, Gastrointestinal Microbiome drug effects, Tryptophan metabolism, Tumor Escape drug effects
- Abstract
Tryptophan metabolism, via the kynurenine (Kyn) pathway, and microbial transformation of tryptophan to indolic compounds are fundamental for host health; both of which are altered in colon carcinogenesis. Alterations in tryptophan metabolism begin early in colon carcinogenesis as an adaptive mechanism for the tumor to escape immune surveillance and metastasize. The microbial community is a key part of the tumor microenvironment and influences cancer initiation, promotion and treatment response. A growing awareness of the impact of the microbiome on tryptophan (Trp) metabolism in the context of carcinogenesis has prompted this review. We first compare the different metabolic pathways of Trp under normal cellular physiology to colon carcinogenesis, in both the host cells and the microbiome. Second, we review how the microbiome, specifically indoles, influence host tryptophan pathways under normal and oncogenic metabolism. We conclude by proposing several dietary, microbial and drug therapeutic modalities that can be utilized in combination to abrogate tumorigenesis.
- Published
- 2021
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16. Exploration of the Vaginal and Gut Microbiome in African American Women by Body Mass Index, Class of Obesity, and Gestational Weight Gain: A Pilot Study.
- Author
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Faucher MA, Greathouse KL, Hastings-Tolsma M, Padgett RN, Sakovich K, Choudhury A, Sheikh A, Ajami NJ, and Petrosino JF
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- Adult, Black or African American, Bacteria classification, Bacteria genetics, Bacteria isolation & purification, Female, Genes, rRNA, High-Throughput Nucleotide Sequencing, Humans, Pilot Projects, Pregnancy, Prospective Studies, RNA, Ribosomal, 16S genetics, Young Adult, Gastrointestinal Microbiome genetics, Gestational Weight Gain genetics, Obesity, Vagina microbiology, Weight Gain
- Abstract
Objective: This study determines the differences in the distal gut and vaginal microbiome in African American (AA) women by prepregnancy body mass index and gestational weight gain (GWG) comparing women with and without obesity and by obesity class., Study Design: We prospectively sampled the vaginal and distal gut microbiome in pregnant AA women at two time points during pregnancy. Samples were analyzed using high-throughput sequencing of the V4 region of the 16S ribosomal ribonucleic acid gene., Results: Distinct differences in vaginal and distal gut α-diversity were observed at time point 1 between women with and without obesity by total GWG. Significant differences in distal gut β-diversity were also found at time point 1 in obese women by GWG. Within the Bacteroides genus, a significant association was observed by total GWG among obese women which was absent in nonobese women. Women with class III obesity who experienced low GWG had the lowest abundance of distal gut Bacteroides and appreciably higher relative abundance of a consortia of vaginal taxa including Atopobium , Gardnerella , Prevotella , and Sneathia ., Conclusion: These results contribute new evidence showing that GWG in combination with obesity and obesity class is associated with an altered distal gut and vaginal composition early in pregnancy among AA women., Competing Interests: None declared., (Thieme. All rights reserved.)
- Published
- 2020
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17. Cancer-Type-Specific Bacteria: Freeloaders or Partners?
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Greathouse KL, Stone JK, and Harris CC
- Subjects
- Bacteria genetics, Carcinogenesis, Humans, Microbiota, Neoplasms
- Abstract
A paper published in Science probes over 1500 tumor samples from multiple cancer types for markers of a tumor microbiome and viable bacteria. Unique intertumoral and intracellular signatures associated with clinical biomarkers and metabolic pathways provide clues to the roles bacteria play in carcinogenesis., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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18. Author Correction: Interaction between the microbiome and TP53 in human lung cancer.
- Author
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Greathouse KL, White JR, Vargas AJ, Bliskovsky VV, Beck JA, von Muhlinen N, Polley EC, Bowman ED, Khan MA, Robles AI, Cooks T, Ryan BM, Padgett N, Dzutsev AH, Trinchieri G, Pineda MA, Bilke S, Meltzer PS, Hokenstad AN, Stickrod TM, Walther-Antonio MR, Earl JP, Mell JC, Krol JE, Balashov SV, Bhat AS, Ehrlich GD, Valm A, Deming C, Conlan S, Oh J, Segre JA, and Harris CC
- Abstract
Following publication of the original paper [1], the authors submitted a new Additional file 5 to replace the one containing formatting issues. The updated Additional file 5 is published in this correction.
- Published
- 2020
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19. DNA extraction for human microbiome studies: the issue of standardization.
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Greathouse KL, Sinha R, and Vogtmann E
- Subjects
- DNA standards, Feces chemistry, Humans, DNA isolation & purification, Genomics standards, Microbiota
- Abstract
Among the laboratory and bioinformatic processing steps for human microbiome studies, a lack of consistency in DNA extraction methodologies is hindering the ability to compare results between studies and sometimes leading to errant conclusions. The purpose of this article is to highlight the issues related to DNA extraction methods and to suggest minimum standard requirements that should be followed to ensure consistency and reproducibility.
- Published
- 2019
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20. Gut microbiome meta-analysis reveals dysbiosis is independent of body mass index in predicting risk of obesity-associated CRC.
- Author
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Greathouse KL, White JR, Padgett RN, Perrotta BG, Jenkins GD, Chia N, and Chen J
- Abstract
Objective: Obesity is a risk factor for colorectal cancer (CRC), accounting for more than 14% of CRC incidence. Microbial dysbiosis and chronic inflammation are common characteristics in both obesity and CRC. Human and murine studies, together, demonstrate the significant impact of the microbiome in governing energy metabolism and CRC development; yet, little is understood about the contribution of the microbiome to development of obesity-associated CRC as compared to individuals who are not obese., Design: In this study, we conducted a meta-analysis using five publicly available stool and tissue-based 16S rRNA and whole genome sequencing (WGS) data sets of CRC microbiome studies. High-resolution analysis was employed for 16S rRNA data, which allowed us to achieve species-level information to compare with WGS., Results: Characterisation of the confounders between studies, 16S rRNA variable region and sequencing method did not reveal any significant effect on alpha diversity in CRC prediction. Both 16S rRNA and WGS were equally variable in their ability to predict CRC. Results from diversity analysis confirmed lower diversity in obese individuals without CRC; however, no universal differences were found in diversity between obese and non-obese individuals with CRC. When examining taxonomic differences, the probability of being classified as CRC did not change significantly in obese individuals for all taxa tested. However, random forest classification was able to distinguish CRC and non-CRC stool when body mass index was added to the model., Conclusion: Overall, microbial dysbiosis was not a significant factor in explaining the higher risk of colon cancer among individuals with obesity., Competing Interests: Competing interests: JRW is a significant shareholder in the company Resphera Biosciences LLC.
- Published
- 2019
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21. Compositional Analysis of the Human Microbiome in Cancer Research.
- Author
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Morales E, Chen J, and Greathouse KL
- Subjects
- Biological Evolution, Gastrointestinal Microbiome, Humans, Polymerase Chain Reaction, RNA, Ribosomal, 16S, Metagenome, Metagenomics methods, Microbiota, Research
- Abstract
Gut microbial composition has shown to be associated with obesity, diabetes mellitus, inflammatory bowel disease, colitis, autoimmune disorders, and cancer, among other diseases. Microbiome research has significantly evolved through the years and continues to advance as we develop new and better strategies to more accurately measure its composition and function. Careful selection of study design, inclusion and exclusion criteria of participants, and methodology are paramount to accurately analyze microbial structure. Here we present the most up-to-date available information on methods for gut microbial collection and analysis.
- Published
- 2019
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22. Interaction between the microbiome and TP53 in human lung cancer.
- Author
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Greathouse KL, White JR, Vargas AJ, Bliskovsky VV, Beck JA, von Muhlinen N, Polley EC, Bowman ED, Khan MA, Robles AI, Cooks T, Ryan BM, Padgett N, Dzutsev AH, Trinchieri G, Pineda MA, Bilke S, Meltzer PS, Hokenstad AN, Stickrod TM, Walther-Antonio MR, Earl JP, Mell JC, Krol JE, Balashov SV, Bhat AS, Ehrlich GD, Valm A, Deming C, Conlan S, Oh J, Segre JA, and Harris CC
- Subjects
- Adult, Aged, Biodiversity, Comamonadaceae classification, Comamonadaceae physiology, Female, Humans, Male, Middle Aged, Mutation genetics, Neoplasms, Squamous Cell genetics, Neoplasms, Squamous Cell microbiology, Proteobacteria metabolism, Reproducibility of Results, Smokers, Tumor Suppressor Protein p53 metabolism, Lung Neoplasms genetics, Lung Neoplasms microbiology, Microbiota genetics, Tumor Suppressor Protein p53 genetics
- Abstract
Background: Lung cancer is the leading cancer diagnosis worldwide and the number one cause of cancer deaths. Exposure to cigarette smoke, the primary risk factor in lung cancer, reduces epithelial barrier integrity and increases susceptibility to infections. Herein, we hypothesize that somatic mutations together with cigarette smoke generate a dysbiotic microbiota that is associated with lung carcinogenesis. Using lung tissue from 33 controls and 143 cancer cases, we conduct 16S ribosomal RNA (rRNA) bacterial gene sequencing, with RNA-sequencing data from lung cancer cases in The Cancer Genome Atlas serving as the validation cohort., Results: Overall, we demonstrate a lower alpha diversity in normal lung as compared to non-tumor adjacent or tumor tissue. In squamous cell carcinoma specifically, a separate group of taxa are identified, in which Acidovorax is enriched in smokers. Acidovorax temporans is identified within tumor sections by fluorescent in situ hybridization and confirmed by two separate 16S rRNA strategies. Further, these taxa, including Acidovorax, exhibit higher abundance among the subset of squamous cell carcinoma cases with TP53 mutations, an association not seen in adenocarcinomas., Conclusions: The results of this comprehensive study show both microbiome-gene and microbiome-exposure interactions in squamous cell carcinoma lung cancer tissue. Specifically, tumors harboring TP53 mutations, which can impair epithelial function, have a unique bacterial consortium that is higher in relative abundance in smoking-associated tumors of this type. Given the significant need for clinical diagnostic tools in lung cancer, this study may provide novel biomarkers for early detection.
- Published
- 2018
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23. High-resolution profiling of the gut microbiome reveals the extent of Clostridium difficile burden.
- Author
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Daquigan N, Seekatz AM, Greathouse KL, Young VB, and White JR
- Abstract
Microbiome profiling through 16S rRNA gene sequence analysis has proven to be a useful research tool in the study of C. difficile infection (CDI); however, CDI microbiome studies typically report results at the genus level or higher, thus precluding identification of this pathogen relative to other members of the gut microbiota. Accurate identification of C. difficile relative to the overall gut microbiome may be useful in assessments of colonization in research studies or as a prognostic indicator for patients with CDI. To investigate the burden of C. difficile at the species level relative to the overall gut microbiome, we applied a high-resolution method for 16S rRNA sequence assignment to previously published gut microbiome studies of CDI and other patient populations. We identified C. difficile in 131 of 156 index cases of CDI (average abundance 1.78%), and 18 of 211 healthy controls (average abundance 0.008%). We further detected substantial levels of C. difficile in a subset of infants that persisted over the first two to 12 months of life. Correlation analysis of C. difficile burden compared to other detected species demonstrated consistent negative associations with C. scindens and multiple Blautia species. These analyses contribute insight into the relative burden of C. difficile in the gut microbiome for multiple patient populations, and indicate that high-resolution 16S rRNA gene sequence analysis may prove useful in the development and evaluation of new therapies for CDI.
- Published
- 2017
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- View/download PDF
24. The Gut Microbiome, Obesity, and Weight Control in Women's Reproductive Health.
- Author
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Greathouse KL, Faucher MA, and Hastings-Tolsma M
- Subjects
- Clinical Nursing Research, Female, Humans, Obesity metabolism, Pregnancy, Pregnancy Outcome, Gastrointestinal Microbiome, Obesity microbiology, Reproductive Health, Women's Health
- Abstract
The microbes residing in the human gut, referred to as the microbiome, are intricately linked to energy homeostasis and subsequently obesity. Integral to the origins of obesity, the microbiome is believed to affect not only health of the human gut but also overall health. This microbiome-obesity association is mediated through the process of energy extraction, metabolism, and cross talk between the brain and the gut microbiome. Host exposures, including diet, that potentially modify genetic predisposition to obesity and affect weight management are reviewed. The higher prevalence of obesity among women and recent evidence linking obesity during pregnancy with offspring health make this topic particularly relevant. Current limitations in microbiome research to address obesity and future advances in this field are described. Applications of this science with respect to applied nursing and overall health care in general are included, with emphasis on the reproductive health of women and their offspring.
- Published
- 2017
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25. Short Course in the Microbiome.
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Falana K, Knight R, Martin CR, Goldszmid R, Greathouse KL, Gere J, Young H, and Kuo WP
- Abstract
Over the past decade, it has become evident that the microbiome is an important environmental factor that affects many physiological processes, such as cell proliferation and differentiation, behaviour, immune function and metabolism. More importantly, it may contribute to a wide variety of diseases, including cancer, inflammatory diseases, metabolic diseases and responses to pathogens. We expect that international, integrative and interdisciplinary translational research teams, along with the emergence of FDA-approved platforms, will set the framework for microbiome-based therapeutics and diagnostics. We recognize that the microbiome ecosystem offers new promise for personalized/precision medicine and targeted treatment for a variety of diseases. The short course was held as a four-session webinar series in April 2015, taught by pioneers and experts in the microbiome ecosystem, covering a broad range of topics from the healthy microbiome to the effects of an altered microbiome from neonates to adults and the long term effects as it is related to disease, from asthma to cancer. We have learned to appreciate how beneficial our microbes are in breaking down our food, fighting off infections and nurturing our immune system, and this information provides us with ideas as to how we can manipulate our microbiome to prevent certain diseases. However, given the variety of applications, there are scientific challenges, though there are very promising areas in reference to the clinical benefits of understanding more about our microbiome, whether in our gut or on our skin: the outlook is bright. A summary of the short course is presented as a meeting dispatch.
- Published
- 2015
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26. Dysfunctional families: Clostridium scindens and secondary bile acids inhibit the growth of Clostridium difficile.
- Author
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Greathouse KL, Harris CC, and Bultman SJ
- Subjects
- Animals, Female, Humans, Bile Acids and Salts metabolism, Clostridioides difficile physiology, Disease Susceptibility microbiology, Intestinal Mucosa metabolism, Intestines microbiology, Microbiota physiology
- Abstract
C. difficile infection is a deadly disease that is influenced by the microbiome. In a recent article in Nature, Buffie et al. (2014) demonstrate that the ability of C. scindens to synthesize secondary bile acids is crucial to providing resistance to C. difficile infection., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
27. A DRD1 polymorphism predisposes to lung cancer among those exposed to secondhand smoke during childhood.
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Robles AI, Yang P, Jen J, McClary AC, Calhoun K, Bowman ED, Vähäkangas K, Greathouse KL, Wang Y, Olivo-Marston S, Wenzlaff AS, Deng B, Schwartz AG, and Ryan BM
- Subjects
- 3' Untranslated Regions genetics, Aged, Case-Control Studies, Child, Cytochrome P-450 CYP2A6 genetics, Female, Follow-Up Studies, Humans, Lung Neoplasms pathology, Male, MicroRNAs genetics, Middle Aged, Neoplasm Staging, Prognosis, Receptors, Nicotinic genetics, Risk Factors, Disease Susceptibility, Lung Neoplasms etiology, Polymorphism, Genetic genetics, Receptors, Dopamine D1 genetics, Smoking genetics, Tobacco Smoke Pollution adverse effects
- Abstract
Lung cancer has a familial component which suggests a genetic contribution to its etiology. Given the strong evidence linking smoking with lung cancer, we studied miRNA-related loci in genes associated with smoking behavior. CHRNA, CHRNB gene families, CYP2A6, and DRD1 (dopamine receptor D1) were mined for SNPs that fell within the seed region of miRNA binding sites and then tested for associations with risk in a three-stage validation approach. A 3'UTR (untranslated region) SNP in DRD1 was associated with a lower risk of lung cancer among individuals exposed to secondhand smoke during childhood [OR, 0.69; 95% confidence interval (CI), 0.60-0.79; P < 0.0001]. This relationship was evident in both ever (OR, 0.74; 95% CI, 0.62-0.88; P = 0.001) and never smokers (OR, 0.61; 95% CI, 0.47-0.79; P < 0.0001), European American (OR, 0.65; 95% CI, 0.53-0.80; P < 0.0001), and African American (OR, 0.73; 95% CI, 0.62-0.88; P = 0.001) populations. Although much remains undefined about the long-term risks associated with exposure to secondhand smoke and heterogeneity between individuals in regard to their susceptibility to the effects of secondhand smoke, our data show an interaction between an SNP in the 3'UTR of DRD1 and exposure to secondhand smoke during childhood. Further work is needed to explore the mechanistic underpinnings of this SNP and the nature of the interaction between DRD1 and exposure to secondhand smoke during childhood., (©2014 American Association for Cancer Research.)
- Published
- 2014
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28. The association of soda sales tax and school nutrition laws: a concordance of policies.
- Author
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Greathouse KL, Chriqui J, Moser RP, Agurs-Collins T, and Perna FM
- Subjects
- Adolescent, Carbonated Beverages economics, Child, Food Dispensers, Automatic economics, Food Dispensers, Automatic legislation & jurisprudence, Guideline Adherence, Humans, Practice Guidelines as Topic, State Government, United States, Young Adult, Carbonated Beverages adverse effects, Food Services economics, Food Services legislation & jurisprudence, Models, Economic, Nutrition Policy legislation & jurisprudence, Schools economics, Schools legislation & jurisprudence, Taxes economics, Taxes legislation & jurisprudence
- Abstract
Objective: The current research examined the association between state disfavoured tax on soda (i.e. the difference between soda sales tax and the tax on food products generally) and a summary score representing the strength of state laws governing competitive beverages (beverages that compete with the beverages in the federally funded school lunch programme) in US schools., Design: The Classification of Laws Associated with School Students (CLASS) summary score reflected the strength of a state's laws restricting competitive beverages sold in school stores, vending machines, school fundraisers and à la carte cafeteria items. Bridging the Gap (BTG) is a nationally recognized research initiative that provided state-level soda tax data. The main study outcome was the states' competitive beverage summary scores for elementary, middle and high school grade levels, as predicted by the states' disfavoured soda tax. Univariate and multivariate analyses were conducted, adjusting for year and state., Setting: Data from BTG and CLASS were used., Subjects: BTG and CLASS data from all fifty states and the District of Columbia from 2003 to 2010 were used., Results: A higher disfavoured soda sales tax was generally associated with an increased likelihood of having strong school beverage laws across grade levels, and especially when disfavoured soda sales tax was >5 %., Conclusions: These data suggest a concordance between states' soda taxes and laws governing beverages sold in schools. States with high disfavoured sales tax on soda had stronger competitive beverage laws, indicating that the state sales tax environment may be associated with laws governing beverage policy in schools.
- Published
- 2014
- Full Text
- View/download PDF
29. Environmental estrogens differentially engage the histone methyltransferase EZH2 to increase risk of uterine tumorigenesis.
- Author
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Greathouse KL, Bredfeldt T, Everitt JI, Lin K, Berry T, Kannan K, Mittelstadt ML, Ho SM, and Walker CL
- Subjects
- Animals, Cell Transformation, Neoplastic metabolism, DNA-Binding Proteins genetics, Enhancer of Zeste Homolog 2 Protein, Estrogens chemical synthesis, Estrogens metabolism, Female, Gene Expression Regulation, Developmental drug effects, Histone Methyltransferases, Histone-Lysine N-Methyltransferase genetics, Humans, Immunohistochemistry, Polycomb Repressive Complex 2, Rats, Risk Factors, Signal Transduction, Transcription Factors genetics, Uterine Neoplasms enzymology, Uterine Neoplasms pathology, Cell Transformation, Neoplastic genetics, DNA-Binding Proteins metabolism, Estrogens pharmacology, Genistein pharmacology, Histone-Lysine N-Methyltransferase metabolism, Transcription Factors metabolism, Uterine Neoplasms chemically induced
- Abstract
Environmental exposures during sensitive windows of development can reprogram normal physiologic responses and alter disease susceptibility later in life in a process known as developmental reprogramming. For example, exposure to the xenoestrogen diethylstilbestrol during reproductive tract development can reprogram estrogen-responsive gene expression in the myometrium, resulting in hyperresponsiveness to hormone in the adult uterus and promotion of hormone-dependent uterine leiomyoma. We show here that the environmental estrogens genistein, a soy phytoestrogen, and the plasticizer bisphenol A, differ in their pattern of developmental reprogramming and promotion of tumorigenesis (leiomyomas) in the uterus. Whereas both genistein and bisphenol A induce genomic estrogen receptor (ER) signaling in the developing uterus, only genistein induced phosphoinositide 3-kinase (PI3K)/AKT nongenomic ER signaling to the histone methyltransferase enhancer of zeste homolog 2 (EZH2). As a result, this pregenomic signaling phosphorylates and represses EZH2 and reduces levels of H3K27me3 repressive mark in chromatin. Furthermore, only genistein caused estrogen-responsive genes in the adult myometrium to become hyperresponsive to hormone; estrogen-responsive genes were repressed in bisphenol A-exposed uteri. Importantly, this pattern of EZH2 engagement to decrease versus increase H3K27 methylation correlated with the effect of these xenoestrogens on tumorigenesis. Developmental reprogramming by genistein promoted development of uterine leiomyomas, increasing tumor incidence and multiplicity, whereas bisphenol A did not. These data show that environmental estrogens have distinct nongenomic effects in the developing uterus that determines their ability to engage the epigenetic regulator EZH2, decrease levels of the repressive epigenetic histone H3K27 methyl mark in chromatin during developmental reprogramming, and promote uterine tumorigenesis.
- Published
- 2012
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30. Xenoestrogen-induced regulation of EZH2 and histone methylation via estrogen receptor signaling to PI3K/AKT.
- Author
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Bredfeldt TG, Greathouse KL, Safe SH, Hung MC, Bedford MT, and Walker CL
- Subjects
- Animals, Blotting, Western, Cell Line, Tumor, Enhancer of Zeste Homolog 2 Protein, Estradiol pharmacology, Female, Genotype, Histones metabolism, Humans, Immunoprecipitation, Methylation drug effects, Mice, Phosphorylation drug effects, Polycomb Repressive Complex 2, Polymerase Chain Reaction, Rats, Signal Transduction drug effects, Signal Transduction genetics, Uterus metabolism, DNA-Binding Proteins metabolism, Diethylstilbestrol pharmacology, Phosphatidylinositol 3-Kinases metabolism, Receptors, Estrogen metabolism, Transcription Factors metabolism
- Abstract
Although rapid, membrane-activated estrogen receptor (ER) signaling is no longer controversial, the biological function of this nongenomic signaling is not fully characterized. We found that rapid signaling from membrane-associated ER regulates the histone methyltransferase enhancer of Zeste homolog 2 (EZH2). In response to both 17beta-estradiol (E2) and the xenoestrogen diethylstilbestrol, ER signaling via phosphatidylinositol 3-kinase/protein kinase B phosphorylates EZH2 at S21, reducing levels of trimethylation of lysine 27 on histone H3 in hormone-responsive cells. During windows of uterine development that are susceptible to developmental reprogramming, activation of this ER signaling pathway by diethylstilbestrol resulted in phosphorylation of EZH2 and reduced levels of trimethylation of lysine 27 on histone H3 in chromatin of the developing uterus. Furthermore, activation of nongenomic signaling reprogrammed the expression profile of estrogen-responsive genes in uterine myometrial cells, suggesting this as a potential mechanism for developmental reprogramming caused by early-life exposure to xenoestrogens. These data demonstrate that rapid ER signaling provides a direct linkage between xenoestrogen-induced nuclear hormone receptor signaling and modulation of the epigenetic machinery during tissue development.
- Published
- 2010
- Full Text
- View/download PDF
31. Identification of uterine leiomyoma genes developmentally reprogrammed by neonatal exposure to diethylstilbestrol.
- Author
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Greathouse KL, Cook JD, Lin K, Davis BJ, Berry TD, Bredfeldt TG, and Walker CL
- Subjects
- Animals, Female, Gene Expression Regulation, Neoplastic, Leiomyoma chemically induced, Mice, Oligonucleotide Array Sequence Analysis, Pregnancy, RNA, Messenger biosynthesis, RNA, Messenger genetics, Rats, Uterine Neoplasms chemically induced, Diethylstilbestrol toxicity, Estrogens, Non-Steroidal toxicity, Gene Expression Regulation, Developmental drug effects, Leiomyoma genetics, Uterine Neoplasms genetics
- Abstract
Environmental exposures during development can alter susceptibility later in life to adult diseases including uterine leiomyoma, a phenomenon termed developmental reprogramming. The goal of this study was to identify genes developmentally reprogrammed by diethylstilbestrol (DES) and aberrantly expressed in leiomyomas. Transcriptional profiling identified 171 genes differentially expressed in leiomyomas relative to normal myometrium, of which 6/18 genes with putative estrogen responsive elements and confirmed to be estrogen-responsive in neonatal uteri were reprogrammed by neonatal DES exposure. Calbindin D9k and Dio2, normally induced by estrogen, exhibited elevated expression in DES-exposed animals during both phases of the estrus cycle. Gdf10, Car8, Gria2, and Mmp3, genes normally repressed by estrogen, exhibited elevated expression in DES-exposed animals during the proliferative phase, when estrogen is highest. These data demonstrate that neonatal DES exposure causes reprogramming of estrogen-responsive genes expressed in uterine leiomyomas, leading to over-expression of these genes in the myometrium of exposed animals prior to the onset of tumorigenesis.
- Published
- 2008
- Full Text
- View/download PDF
32. Effects of increased dietary fat and exercise on skeletal muscle lipid peroxidation and antioxidant capacity in male rats.
- Author
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Greathouse KL, Samuels M, DiMarco NM, and Criswell DS
- Subjects
- Animals, Citrate (si)-Synthase metabolism, Energy Metabolism physiology, Glutathione Peroxidase metabolism, Humans, Male, Muscle, Skeletal metabolism, Oxidation-Reduction, Random Allocation, Rats, Rats, Sprague-Dawley, Superoxide Dismutase metabolism, Antioxidants metabolism, Dietary Fats, Unsaturated pharmacology, Lipid Peroxidation drug effects, Muscle, Skeletal enzymology, Physical Conditioning, Animal physiology
- Abstract
Background: Elevated dietary fat increases oxidative metabolism and has been linked to increased oxidative stress, while exercise training may augment antioxidant capacity. Most studies examining oxidative stress in skeletal muscle employ extremely high levels of dietary fat and/or intense exercise training that may not adequately model human diet and activity patterns., Aim: The purpose of this study was to examine the interaction between an elevated (40% of calories) monounsaturated fat diet and a moderate-intensity exercise program similar to recommended human exercise prescriptions, on skeletal muscle oxidative stress and antioxidant defenses., Methods: Twenty-four male Sprague-Dawley rats (approximately 500 g) were randomly divided into 4 groups (n = 6/group): Standard Diet-Sedentary (SD-Sed), Standard Diet-Exercise (SD-Ex), Elevated Fat Diet-Sedentary (EFD-Sed), and Elevated Fat Diet-Exercise (EFD-Ex). The SD groups consumed 76% of calories from CHO, 14% from protein, and 10 % from fat, while the EFD groups received a diet of 46% of calories from CHO, 14% from protein, and 40 % from fat (high oleic sunflower oil). The exercise groups were progressively treadmill trained at 20 m/min, 4 days/week increasing from 15 min/day to 35 min/day by the end of 4 wks., Results and Conclusion: Antioxidant adaptations associated with exercise training or an elevated fat diet individually reduced basal lipid peroxidation levels in the plantaris muscle. However, the combination of exercise plus a monounsaturated fat diet increased lipid peroxidation levels above that with either treatment alone. This suggests an exhaustion of the antioxidant capacity in the plantaris muscle when both exercise and increased dietary fat diet are combined.
- Published
- 2005
- Full Text
- View/download PDF
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