Browsing by Subject "oxidative stress"
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Item Association Between Residential Greenness and Cardiovascular Disease Risk(Wiley, 2018-12-05) Yeager, Ray; Riggs, Daniel W.; DeJarnett, Natasha; Tollerud, David J.; Wilson, Jeffrey; Conklin, Daniel J.; O'Toole, Timothy E.; McCracken, James; Lorkiewicz, Pawel; Xie, Zhengzhi; Zafar, Nagma; Krishnasamy, Sathya S.; Srivastava, Sanjay; Finch, Jordan; Keith, Rachel J.; DeFilippis, Andrew; Rai, Shesh N.; Liu, Gilbert; Bhatnagar, Aruni; Department of Geography, School of Liberal ArtsBackground Exposure to green vegetation has been linked to positive health, but the pathophysiological processes affected by exposure to vegetation remain unclear. To study the relationship between greenness and cardiovascular disease, we examined the association between residential greenness and biomarkers of cardiovascular injury and disease risk in susceptible individuals. Methods and Results In this cross‐sectional study of 408 individuals recruited from a preventive cardiology clinic, we measured biomarkers of cardiovascular injury and risk in participant blood and urine. We estimated greenness from satellite‐derived normalized difference vegetation index (NDVI) in zones with radii of 250 m and 1 km surrounding the participants’ residences. We used generalized estimating equations to examine associations between greenness and cardiovascular disease biomarkers. We adjusted for residential clustering, demographic, clinical, and environmental variables. In fully adjusted models, contemporaneous NDVI within 250 m of participant residence was inversely associated with urinary levels of epinephrine (−6.9%; 95% confidence interval, −11.5, −2.0/0.1 NDVI) and F2‐isoprostane (−9.0%; 95% confidence interval, −15.1, −2.5/0.1 NDVI). We found stronger associations between NDVI and urinary epinephrine in women, those not on β‐blockers, and those who had not previously experienced a myocardial infarction. Of the 15 subtypes of circulating angiogenic cells examined, 11 were inversely associated (8.0–15.6% decrease/0.1 NDVI), whereas 2 were positively associated (37.6–45.8% increase/0.1 NDVI) with contemporaneous NDVI. Conclusions Independent of age, sex, race, smoking status, neighborhood deprivation, statin use, and roadway exposure, residential greenness is associated with lower levels of sympathetic activation, reduced oxidative stress, and higher angiogenic capacity.Item Haptoglobin 2 Allele is Associated With Histologic Response to Vitamin E in Subjects With Nonalcoholic Steatohepatitis(Wolters Kluwer, 2020-11) Banini, Bubu A.; Cazanave, Sophie C.; Yates, Katherine P.; Asgharpour, Amon; Vincent, Robert; Mirshahi, Faridoddin; Le, Peter; Contos, Melissa J.; Tonascia, James; Chalasani, Naga P.; Kowdley, Kris V.; McCullough, Arthur J.; Behling, Cynthia A.; Schwimmer, Jeffrey B.; Lavine, Joel E.; Sanyal, Arun J.; Medicine, School of MedicineBackground: Haptoglobin (Hp) genotype has been linked to oxidative stress and response to vitamin E (VitE) in patients with dyslipidemia. Its effect on histological response to VitE in nonalcoholic steatohepatitis (NASH) is unknown. Goals: Our objective was to determine if Hp genotype associates with response to VitE in patients with NASH. Study: A post hoc analysis of 228 patients receiving VitE or placebo in two clinical trials was performed. Regression analysis was used to assess the effect of VitE versus placebo, by Hp genotype (1–1, 2–1, or 2–2), on histologic features and laboratory markers of liver disease, comparing baseline to end of treatment values. An interaction term was included in the regression models to assess differential treatment effect across Hp genotype. Results: Hp 2–2 patients treated with VitE versus placebo showed significant histologic improvement (51% versus 20%, OR=4·2, p=0·006), resolution of steatohepatitis (44% versus 12%, OR=6.2, p=0·009), decrease in NAFLD Activity Score (NAS) (−2·2 versus −0·6, p=0·001), and decrease in liver enzymes alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyl transpeptidase. Hp 2–1 patients on VitE versus placebo showed improved resolution of steatohepatitis, NAS and liver enzymes. Hp 1–1 patients showed no significant improvement in histology or liver enzymes. VitE had no effect on fibrosis stage in any group. Regression analysis showed incremental benefit of having Hp 2–2 or 2–1 versus 1–1 for all liver enzymes. Conclusion: Hp 2 allele is associated with greater histological and biological improvement in NASH with VitE treatment compared to the Hp 1 allele.Item Methylmercury exposure increases lipocalin related (lpr) and decreases activated in blocked unfolded protein response (abu) genes and specific miRNAs in Caenorhabditis elegans(Elsevier, 2013-10-24) Rudgalvyte, Martina; VanDuyn, Natalia; Aarnio, Vuokko; Heikkinen, Liisa; Peltonen, Juhani; Lakso, Merja; Nass, Richard; Wong, Garry; Department of Pharmacology and Toxicology, School of MedicineMethylmercury (MeHg) is a persistent environmental and dietary contaminant that causes serious adverse developmental and physiologic effects at multiple cellular levels. In order to understand more fully the consequences of MeHg exposure at the molecular level, we profiled gene and miRNA transcripts from the model organism Caenorhabditis elegans. Animals were exposed to MeHg (10µM) from embryo to larval 4 (L4) stage and RNAs were isolated. RNA-seq analysis on the Illumina platform revealed 541 genes up- and 261 genes down-regulated at a cutoff of 2-fold change and false discovery rate-corrected significance q < 0.05. Among the up-regulated genes were those previously shown to increase under oxidative stress conditions including hsp-16.11 (2.5-fold), gst-35 (10.1-fold), and fmo-2(58.5-fold). In addition, we observed up-regulation of 6 out of 7 lipocalin related (lpr) family genes and down regulation of 7 out of 15 activated in blocked unfolded protein response (abu) genes. Gene Ontology enrichment analysis highlighted the effect of genes related to development and organism growth. miRNA-seq analysis revealed 6–8 fold down regulation of mir-37-3p, mir-41-5p, mir-70-3p, and mir-75-3p. Our results demonstrate the effects of MeHg on specific transcripts encoding proteins in oxidative stress responses and in ER stress pathways. Pending confirmation of these transcript changes at protein levels, their association and dissocation characteristics with interaction partners, and integration of these signals, these findings indicate broad and dynamic mechanisms by which MeHg exerts its harmful effects.Item Molecular Mechanisms of Nonalcoholic Fatty Liver Disease: Potential Role for 12-Lipoxygenase(Elsevier, 2017) Samala, Niharika; Tersey, Sarah A.; Chalasani, Naga; Anderson, Ryan M.; Mirmira, Raghavendra G.; Department of Biochemistry and Molecular Biology, School of MedicineNonalcoholic fatty liver disease (NAFLD) is a spectrum of pathologies associated with fat accumulation in the liver. NAFLD is the most common cause of liver disease in the United States, affecting up to a third of the general population. It is commonly associated with features of metabolic syndrome, particularly insulin resistance. NAFLD shares the basic pathogenic mechanisms with obesity and insulin resistance, such as mitochondrial, oxidative and endoplasmic reticulum stress. Lipoxygenases catalyze the conversion of poly-unsaturated fatty acids in the plasma membrane—mainly arachidonic acid and linoleic acid—to produce oxidized pro-inflammatory lipid intermediates. 12-Lipoxygenase (12-LOX) has been studied extensively in setting of inflammation and insulin resistance. As insulin resistance is closely associated with development of NAFLD, the role of 12-LOX in pathogenesis of NAFLD has received increasing attention in recent years. In this review we discuss the role of 12-LOX in NAFLD pathogenesis and its potential role in emerging new therapeutics.Item Neonatal hyperoxia promotes asthma-like features through IL-33–dependent ILC2 responses(Elsevier, 2017) Cheon, In Su; Son, Young Min; Jiang, Li; Goplen, Nicholas P.; Kaplan, Mark H.; Limper, Andrew H.; Kita, Hirohito; Paczesny, Sophie; Prakash, Y. S.; Tepper, Robert; Ahlfeld, Shawn K.; Sun, Jie; Pediatrics, School of MedicineBackground Premature infants often require oxygen supplementation and, therefore, are exposed to oxidative stress. Following oxygen exposure, preterm infants frequently develop chronic lung disease and have a significantly increased risk of asthma. Objective We sought to identify the underlying mechanisms by which neonatal hyperoxia promotes asthma development. Methods Mice were exposed to neonatal hyperoxia followed by a period of room air recovery. A group of mice was also intranasally exposed to house dust mite antigen. Assessments were performed at various time points for evaluation of airway hyperresponsiveness, eosinophilia, mucus production, inflammatory gene expression, and TH and group 2 innate lymphoid cell (ILC2) responses. Sera from term- and preterm-born infants were also collected and levels of IL-33 and type 2 cytokines were measured. Results Neonatal hyperoxia induced asthma-like features including airway hyperresponsiveness, mucus hyperplasia, airway eosinophilia, and type 2 pulmonary inflammation. In addition, neonatal hyperoxia promoted allergic TH responses to house dust mite exposure. Elevated IL-33 levels and ILC2 responses were observed in the lungs most likely due to oxidative stress caused by neonatal hyperoxia. IL-33 receptor signaling and ILC2s were vital for the induction of asthma-like features following neonatal hyperoxia. Serum IL-33 levels correlated significantly with serum levels of IL-5 and IL-13 but not IL-4 in preterm infants. Conclusions These data demonstrate that an axis involving IL-33 and ILC2s is important for the development of asthma-like features following neonatal hyperoxia and suggest therapeutic potential for targeting IL-33, ILC2s, and oxidative stress to prevent and/or treat asthma development related to prematurity.Item New Insights in the Pathogenesis of Multiple Sclerosis—Role of Acrolein in Neuronal and Myelin Damage(MDPI, 2013-10-09) Tully, Melissa; Shi, Riyi; Medicine, School of MedicineMultiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by an inappropriate inflammatory reaction resulting in widespread myelin injury along white matter tracts. Neurological impairment as a result of the disease can be attributed to immune-mediated injury to myelin, axons and mitochondria, but the molecular mechanisms underlying the neuropathy remain incompletely understood. Incomplete mechanistic knowledge hinders the development of therapies capable of alleviating symptoms and slowing disease progression in the long-term. Recently, oxidative stress has been implicated as a key component of neural tissue damage prompting investigation of reactive oxygen species (ROS) scavengers as a potential therapeutic option. Despite the establishment of oxidative stress as a crucial process in MS development and progression, ROS scavengers have had limited success in animal studies which has prompted pursuit of an alternative target capable of curtailing oxidative stress. Acrolein, a toxic β-unsaturated aldehyde capable of initiating and perpetuating oxidative stress, has been suggested as a viable point of intervention to guide the development of new treatments. Sequestering acrolein using an FDA-approved compound, hydralazine, offers neuroprotection resulting in dampened symptom severity and slowed disease progression in experimental autoimmune encephalomyelitis (EAE) mice. These results provide promise for therapeutic development, indicating the possible utility of neutralizing acrolein to preserve and improve neurological function in MS patients.Item Nrf2 Deficiency Augments the Activity of Hepatic Progenitor Cells during Cholestasis(Office of the Vice Chancellor for Research, 2013-04-05) Wang, Guo-Ying; Zou, Yuhong; Dai, GuoliTranscription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a central regulator of cellular defense against oxidative stress and inflammation and is also involved in regulating liver regeneration. The aim of the study is to evaluate whether Nrf2 mediates hepatic repair response during cholestasis. Wild-type and Nrf2-null mice were subjected to bile duct ligation or sham operation. Various assessments were performed at 5, 10, 15, 25, and 40 days following surgery. Significant genotype-dependent differences in liver injury, cell proliferation, and collagen deposition were not seen over the time course of the study, in line with several reports. However, Nrf2-null mice exhibited a more prominent network of septual tissue containing laminin and α-fetal protein expressing cells at 15 days after injury, suggesting a stronger repair response, than their wild-type litter mates. In the livers of both genotypes of mice, cytokeratin 19 (CK19), a marker of bipotent liver epithelial progenitors and immature billiary epithelial cells, were expressed in the epithelial cells of newly formed bile ducts and a population of hepatocytic-appearing cells in parenchyma. Notably, Nrf2-null mice showed higher hepatic protein expression of CK19 at 5 days following BDL, indicating earlier onset of the activation of CK19+ progenitor cells, than wild-types. CD133, a marker of liver progenitors, were found to be expressed by newly generated bile duct epithelial cells and a population of hepatocytic-appearing parenchymal cells in the livers of the two genotypes of mice. Hepatic CD133 protein expression was gradually elevated, paralleling continuous increase in the number of CD133+ hepatocytic-appearing cells, as the cholestasis progressed. Remarkably, the lack of Nrf2 led to markedly higher magnitudes of the increases in hepatic CD133 protein level and in the number of CD133+ hepatocytic-appearing cells. Collectively, our data demonstrate that Nrf2 deficiency evokes higher activity of liver progenitor cells and thus stronger liver repair response. The findings indicate that Nrf2 is an important regulator of the activity of hepatic progenitor/stem cells during chronic liver injury.Item Pre-diagnostic leukocyte mitochondrial DNA copy number and colorectal cancer risk(Oxford, 2019-09) Yang, Keming; Li, Xin; Forman, Michele R.; Monahan, Patrick O.; Graham, Bret H.; Joshi, Amit; Song, Mingyang; Hang, Dong; Ogino, Shuji; Giovannucci, Edward L.; De Vivo, Immaculata; Chan, Andrew T.; Nan, Hongmei; Epidemiology, School of Public HealthMitochondrial DNA (mtDNA) is susceptible to oxidative stress and mutation. Few epidemiological studies have assessed the relationship between mtDNA copy number (mtDNAcn) and risk of colorectal cancer (CRC), with inconsistent findings. In this study, we examined the association between pre-diagnostic leukocyte mtDNAcn and CRC risk in a case–control study of 324 female cases and 658 matched controls nested within the Nurses’ Health Study (NHS). Relative mtDNAcn in peripheral blood leukocytes was measured by quantitative polymerase chain reaction-based assay. Conditional logistic regression models were applied to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association of interest. Results showed lower log-mtDNAcn was significantly associated with increased risk of CRC, in a dose-dependent relationship (P for trend < 0.0001). Compared to the fourth quartile, multivariable-adjusted OR [95% confidence interval (CI)] was 1.10 (0.69, 1.76) for the third quartile, 1.40 (0.89, 2.19) for the second quartile and 2.19 (1.43, 3.35) for the first quartile. In analysis by anatomic subsite of CRC, we found a significant inverse association for proximal colon cancer [lowest versus highest quartile, multivariable-adjusted OR (95% CI) = 3.31 (1.70, 6.45), P for trend = 0.0003]. Additionally, stratified analysis according to the follow-up time since blood collection showed that the inverse association between mtDNAcn and CRC remained significant among individuals with ≥ 5 years’ follow-up, and marginally significant among those with ≥ 10 years’ follow-up since mtDNAcn testing, suggesting that mtDNAcn may serve as a long-term predictor for risk of CRC. In conclusion, pre-diagnostic leukocyte mtDNAcn was inversely associated with CRC risk. Further basic experimental studies are needed to explore the underlying biological mechanisms linking mtDNAcn to CRC carcinogenesis.Item A Randomized, Placebo-Controlled Pilot Trial of N-Acetylcysteine on Oxidative Stress and Endothelial Function in HIV-infected Older Adults Receiving ART(Wolters Kluwer, 2016-09-24) Gupta, Samir K.; Kamendulis, Lisa M.; Clauss, Matthias A.; Liu, Ziyue; Medicine, School of MedicineItem Reduced proliferation of endothelial colony-forming cells in unprovoked venous thromboembolic disease as a consequence of endothelial dysfunction(PLOS, 2017-09-14) Hernandez-Lopez, Rubicel; Chavez-Gonzalez, Antonieta; Torres-Barrera, Patricia; Moreno-Lorenzana, Dafne; Lopez-DiazGuerrero, Norma; Santiago-German, David; Isordia-Salas, Irma; Smadja, David; C. Yoder, Mervin; Majluf-Cruz, Abraham; Alvarado-Moreno, J. Antonio; Pediatrics, School of MedicineBackground Venous thromboembolic disease (VTD) is a public health problem. We recently reported that endothelial colony-forming cells (ECFCs) derived from endothelial cells (EC) (ECFC-ECs) from patients with VTD have a dysfunctional state. For this study, we proposed that a dysfunctional status of these cells generates a reduction of its proliferative ability, which is also associated with senescence and reactive oxygen species (ROS). Methods and results Human mononuclear cells (MNCs) were obtained from peripheral blood from 40 healthy human volunteers (controls) and 50 patients with VTD matched by age (20−50 years) and sex to obtain ECFCs. We assayed their proliferative ability with plasma of patients and controls and supernatants of cultures from ECFC-ECs, senescence-associated β-galactosidase (SA-β-gal), ROS, and expression of ephrin-B2/Eph-B4 receptor. Compared with cells from controls, cells from VTD patients showed an 8-fold increase of ECFCs that emerged 1 week earlier, reduced proliferation at long term (39%) and, in passages 4 and 10, a highly senescent rate (30±1.05% vs. 91.3±15.07%, respectively) with an increase of ROS and impaired expression of ephrin-B2/Eph-4 genes. Proliferation potential of cells from VTD patients was reduced in endothelial medium [1.4±0.22 doubling population (DP)], control plasma (1.18±0.31 DP), or plasma from VTD patients (1.65±0.27 DP). Conclusions As compared with controls, ECFC-ECs from individuals with VTD have higher oxidative stress, proliferation stress, cellular senescence, and low proliferative potential. These findings suggest that patients with a history of VTD are ECFC-ECs dysfunctional that could be associated to permanent risk for new thrombotic events.