scholarly journals Antioxidants Promote Intestinal Tumor Progression in Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 241
Author(s):  
Zhiyuan V. Zou ◽  
Kristell Le Gal ◽  
Ahmed E. El Zowalaty ◽  
Lara E. Pehlivanoglu ◽  
Viktor Garellick ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Colorectal Cancer ◽  
Tumor Progression ◽  
Human Subjects ◽  
Plasma Concentrations ◽  
Intestinal Tumor ◽  
Adenomatous Polyposis ◽  
Intestinal Tumors ◽  
The Impact

Dietary antioxidants and supplements are widely used to protect against cancer, even though it is now clear that antioxidants can promote tumor progression by helping cancer cells to overcome barriers of oxidative stress. Although recent studies have, in great detail, explored the role of antioxidants in lung and skin tumors driven by RAS and RAF mutations, little is known about the impact of antioxidant supplementation on other cancers, including Wnt-driven tumors originating from the gut. Here, we show that supplementation with the antioxidants N-acetylcysteine (NAC) and vitamin E promotes intestinal tumor progression in the ApcMin mouse model for familial adenomatous polyposis, a hereditary form of colorectal cancer, driven by Wnt signaling. Both antioxidants increased tumor size in early neoplasias and tumor grades in more advanced lesions without any impact on tumor initiation. Importantly, NAC treatment accelerated tumor progression at plasma concentrations comparable to those obtained in human subjects after prescription doses of the drug. These results demonstrate that antioxidants play an important role in the progression of intestinal tumors, which may have implications for patients with or predisposed to colorectal cancer.

Pharmacological inhibition to examine the role of DGAT1 in dietary lipid absorption in rodents and humans

2013 ◽  
Vol 304 (11) ◽  
pp. G958-G969 ◽  
Author(s):  
Benjamin S. Maciejewski ◽  
Jennifer L. LaPerle ◽  
Danny Chen ◽  
Avijit Ghosh ◽  
William J. Zavadoski ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Human Subjects ◽  
Plasma Concentrations ◽  
Large Family ◽  
Dietary Lipid ◽  
Lipid Absorption ◽  
Pharmacological Intervention ◽  
Dependent Inhibition ◽  
The Impact

Alterations in fat metabolism, in particular elevated plasma concentrations of free fatty acids and triglycerides (TG), have been implicated in the pathogenesis of Type 2 diabetes, obesity, and cardiovascular disease. Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), a member of the large family of membrane-bound O-acyltransferases, catalyzes the final step in triacylglycerol formation. In the intestine, DGAT1 is one of the acyltransferases responsible for the reesterficiation of dietary TG. Following a single dose of a selective pharmacological inhibitor of DGAT1, PF-04620110, a dose-dependent inhibition of TG and vitamin A absorption postprandially was demonstrated in rodents and human subjects. In C57/BL6J mice, acute DGAT1 inhibition alters the temporal and spatial pattern of dietary lipid absorption. To understand the impact of DGAT1 inhibition on enterocyte lipid metabolism, lipomic profiling was performed in rat intestine and plasma as well as human plasma. DGAT1 inhibition causes an enrichment of polyunsaturated fatty acids within the TG class of lipids. This pharmacological intervention gives us insight as to the role of DGAT1 in human dietary lipid absorption.

scholarly journals Protective role of ABCG2 against oxidative stress in colorectal cancer and its potential underlying mechanism

2018 ◽  
Author(s):  
Shuang Nie ◽  
Yaqing Huang ◽  
Mengyue Shi ◽  
Xuetian Qian ◽  
Hongzhen Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Colorectal Cancer ◽  
Underlying Mechanism ◽  
Protective Role

scholarly journals PmtA Regulates Pyocyanin Expression and Biofilm Formation in Pseudomonas aeruginosa

2021 ◽  
Vol 12 ◽  
Author(s):  
Amy V. Thees ◽  
Kathryn M. Pietrosimone ◽  
Clare K. Melchiorre ◽  
Jeremiah N. Marden ◽  
Joerg Graf ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pseudomonas Aeruginosa ◽  
Metal Binding ◽  
Biofilm Formation ◽  
Binding Capacity ◽  
Opportunistic Pathogen ◽  
Small Molecular Weight ◽  
Heavy Metal Binding ◽  
The Impact

The opportunistic pathogen Pseudomonas aeruginosa expresses a small molecular weight, cysteine-rich protein (PmtA), identified as a metallothionein (MT) protein family member. The MT family proteins have been well-characterized in eukaryotes as essential for zinc and copper homeostasis, protection against oxidative stress, and the ability to modify a variety of immune activities. Bacterial MTs share sequence homology, antioxidant chemistry, and heavy metal-binding capacity with eukaryotic MTs, however, the impact of bacterial MTs on virulence and infection have not been well-studied. In the present study, we investigated the role of PmtA in P. aeruginosa PAO1 using a PmtA-deficient strain (ΔpmtA). Here we demonstrated the virulence factor, pyocyanin, relies on the expression of PmtA. We showed that PmtA may be protective against oxidative stress, as an alternative antioxidant, glutathione, can rescue pyocyanin expression. Furthermore, the expression of phzM, which encodes a pyocyanin precursor enzyme, was decreased in the ΔpmtA mutant during early stationary phase. Upregulated pmtA expression was previously detected in confluent biofilms, which are essential for chronic infection, and we observed that the ΔpmtA mutant was disrupted for biofilm formation. As biofilms also modulate antibiotic susceptibility, we examined the ΔpmtA mutant susceptibility to antibiotics and found that the ΔpmtA mutant is more susceptible to cefepime and ciprofloxacin than the wild-type strain. Finally, we observed that the deletion of pmtA results in decreased virulence in a waxworm model. Taken together, our results support the conclusion that PmtA is necessary for the full virulence of P. aeruginosa and may represent a potential target for therapeutic intervention.

scholarly journals The effect of cigarette smoking on endothelial damage and atherosclerosis development – modeled and analyzed using Petri nets

2017 ◽  
Vol 27 (2) ◽  
pp. 211-228 ◽  
Author(s):  
Kaja Chmielewska ◽  
Dorota Formanowicz ◽  
Piotr Formanowicz
Keyword(s):  
Oxidative Stress ◽  
Petri Nets ◽  
Tobacco Smoke ◽  
Endothelial Damage ◽  
Dual Function ◽  
Contributing Factors ◽  
Atherosclerotic Plaque Formation ◽  
Atherosclerosis Development ◽  
The Impact

Abstract Atherosclerosis as one of the crucial causes of cardiovascular diseases (CVD) is the leading reason of death worldwide. One of the contributing factors to this phenomenon is endothelial dysfunction, which is associated with the impact of various agents and their interactions. Tobacco smoke is one of the well known factors here. For better understanding of its significance a model of its impact on atherosclerotic plaque formation has been proposed. The model contains selected aspects of the influence of tobacco smoke, dual function of nitric oxide (NO) (influence of various mechanisms on NO bioavailability), oxidative stress which promotes low density lipoproteins oxidation, macrophages significance and other mechanisms leading to an aggravation of the endothelial disturbances. The model has been built using Petri nets theory and the analysis has been based on t-invariants. This approach allowed to confirm the important role of inflammation and oxidative stress in atherosclerosis development and moreover it has shown the considerable influence of the cigarette smoke.

scholarly journals Adrenal adaptation in potassium-depleted men: role of progesterone?

2019 ◽  
Vol 35 (11) ◽  
pp. 1901-1908
Author(s):  
Anne Blanchard ◽  
Sylvie Brailly Tabard ◽  
Antonin Lamaziere ◽  
Damien Bergerot ◽  
Valentina Zhygalina ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Human Subjects ◽  
Plasma Concentrations ◽  
Plasma Renin ◽  
Plasma Potassium ◽  
Potassium Depletion ◽  
Healthy Human ◽  
Plasma Aldosterone Concentration ◽  
Tandem Mass Spectroscopy

AbstractBackgroundIn rodents, the stimulation of adrenal progesterone is necessary for renal adaptation under potassium depletion. Here, we sought to determine the role of progesterone in adrenal adaptation in potassium-depleted healthy human volunteers and compared our findings with data collected in patients with Gitelman syndrome (GS), a salt-losing tubulopathy.MethodsTwelve healthy young men were given a potassium-depleted diet for 7 days at a tertiary referral medical centre (NCT02297048). We measured by liquid chromatography coupled to tandem mass spectroscopy plasma steroid concentrations at Days 0 and 7 before and 30 min after treatment with tetracosactide. We compared these data with data collected in 10 GS patients submitted to tetracosactide test.ResultsThe potassium-depleted diet decreased plasma potassium in healthy subjects by 0.3 ± 0.1 mmol/L, decreased plasma aldosterone concentration by 50% (P = 0.0332) and increased plasma 17-hydroxypregnenolone concentration by 45% (P = 0.0232) without affecting other steroids. CYP17 activity, as assessed by 17-hydroxypregnenolone/pregnenolone ratio, increased by 60% (P = 0.0389). As compared with healthy subjects, GS patients had 3-fold higher plasma concentrations of aldosterone, 11-deoxycortisol (+30%) and delta 4-androstenedione (+14%). Their post-tetracosactide progesterone concentration was 2-fold higher than that of healthy subjects and better correlated to plasma potassium than to plasma renin.ConclusionThe increase in 17-hydroxypregnenolone concentration after mild potassium depletion in otherwise healthy human subjects suggests that 17 hydroxylation of pregnenolone prevents the increase in progesterone observed in potassium-depleted mice. The unexpected over-response of non-mineralocorticoid steroids to tetracosactide in GS subjects suggests that the adrenal system not only adapts to sodium depletion but may also respond to hypokalaemia.

scholarly journals Circulating Leukocytes and Oxidative Stress in Cardiovascular Diseases: A State of the Art

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Speranza Rubattu ◽  
Maurizio Forte ◽  
Salvatore Raffa
Keyword(s):  
Oxidative Stress ◽  
Cardiovascular Diseases ◽  
Stress Level ◽  
Mononuclear Cells ◽  
Pathological Condition ◽  
Clinical Manifestations ◽  
Therapeutic Interventions ◽  
Oxidative Stress Level ◽  
The Impact

Increased oxidative stress from both mitochondrial and cytosolic sources contributes to the development and the progression of cardiovascular diseases (CVDs), and it is a target of therapeutic interventions. The numerous efforts made over the last decades in order to develop tools able to monitor the oxidative stress level in patients affected by CVDs rely on the need to gain information on the disease state. However, this goal has not been satisfactorily accomplished until now. Among others, the isolation of circulating leukocytes to measure their oxidant level offers a valid, noninvasive challenge that has been tested in few pathological contexts, including hypertension, atherosclerosis and its clinical manifestations, and heart failure. Since leukocytes circulate in the blood stream, it is expected that they might reflect quite closely both systemic and cardiovascular oxidative stress and provide useful information on the pathological condition. The results of the studies discussed in the present review article are promising. They highlight the importance of measuring oxidative stress level in circulating mononuclear cells in different CVDs with a consistent correlation between degree of oxidative stress and severity of CVD and of its complications. Importantly, they also point to a double role of leukocytes, both as a marker of disease condition and as a direct contributor to disease progression. Finally, they show that the oxidative stress level of leukocytes reflects the impact of therapeutic interventions. It is likely that the isolation of leukocytes and the measurement of oxidative stress, once adequately developed, may represent an eligible tool for both research and clinical purposes to monitor the role of oxidative stress on the promotion and progression of CVDs, as well as the impact of therapies.

scholarly journals Oxidative Stress and Adipocyte Biology: Focus on the Role of AGEs

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Florence Boyer ◽  
Jennifer Baraka Vidot ◽  
Alexis Guerin Dubourg ◽  
Philippe Rondeau ◽  
M. Faadiel Essop ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Adipose Tissue ◽  
Advanced Glycation Endproducts ◽  
Glycated Albumin ◽  
Major Health Problem ◽  
Glycation Endproducts ◽  
Diabetes Progression ◽  
The Impact ◽  
Pathologic Processes

Diabetes is a major health problem that is usually associated with obesity, together with hyperglycemia and increased advanced glycation endproducts (AGEs) formation. Elevated AGEs elicit severe downstream consequences via their binding to receptors of AGEs (RAGE). This includes oxidative stress and oxidative modifications of biological compounds together with heightened inflammation. For example, albumin (major circulating protein) undergoes increased glycoxidation with diabetes and may represent an important biomarker for monitoring diabetic pathophysiology. Despite the central role of adipose tissue in many physiologic/pathologic processes, recognition of the effects of greater AGEs formation in this tissue is quite recent within the obesity/diabetes context. This review provides a brief background of AGEs formation and adipose tissue biology and thereafter discusses the impact of AGEs-adipocyte interactions in pathology progression. Novel data are included showing how AGEs (especially glycated albumin) may be involved in hyperglycemia-induced oxidative damage in adipocytes and its potential links to diabetes progression.

scholarly journals Xanthine oxidase inhibition protects against Western diet-induced aortic stiffness and impaired vasorelaxation in female mice

2017 ◽  
Vol 313 (2) ◽  
pp. R67-R77 ◽  
Author(s):  
Guido Lastra ◽  
Camila Manrique ◽  
Guanghong Jia ◽  
Annayya R. Aroor ◽  
Melvin R. Hayden ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Arterial Stiffness ◽  
Xanthine Oxidase ◽  
Aortic Stiffness ◽  
Plasma Concentrations ◽  
Western Diet ◽  
Vascular Stiffness ◽  
High Fructose ◽  
The Impact

Consumption of a high-fat, high-fructose diet [Western diet (WD)] promotes vascular stiffness, a critical factor in the development of cardiovascular disease (CVD). Obese and diabetic women exhibit greater arterial stiffness than men, which contributes to the increased incidence of CVD in these women. Furthermore, high-fructose diets result in elevated plasma concentrations of uric acid via xanthine oxidase (XO) activation, and uric acid elevation is also associated with increased vascular stiffness. However, the mechanisms by which increased xanthine oxidase activity and uric acid contribute to vascular stiffness in obese females remain to be fully uncovered. Accordingly, we examined the impact of XO inhibition on endothelial function and vascular stiffness in female C57BL/6J mice fed a WD or regular chow for 16 wk. WD feeding resulted in increased arterial stiffness, measured by atomic force microscopy in aortic explants (16.19 ± 1.72 vs. 5.21 ± 0.54 kPa, P < 0.05), as well as abnormal aortic endothelium-dependent and -independent vasorelaxation. XO inhibition with allopurinol (widely utilized in the clinical setting) substantially improved vascular relaxation and attenuated stiffness (16.9 ± 0.50 vs. 3.44 ± 0.50 kPa, P < 0.05) while simultaneously lowering serum uric acid levels (0.55 ± 0.98 vs. 0.21 ± 0.04 mg/dL, P < 0.05). In addition, allopurinol improved WD-induced markers of fibrosis and oxidative stress in aortic tissue, as analyzed by immunohistochemistry and transmission electronic microscopy. Collectively, these results demonstrate that XO inhibition protects against WD-induced vascular oxidative stress, fibrosis, impaired vasorelaxation, and aortic stiffness in females. Furthermore, excessive oxidative stress resulting from XO activation appears to play a key role in mediating vascular dysfunction induced by chronic exposure to WD consumption in females.

scholarly journals The Impact of miRNA in Colorectal Cancer Progression and Its Liver Metastases

2018 ◽  
Vol 19 (12) ◽  
pp. 3711 ◽  
Author(s):  
Ovidiu Balacescu ◽  
Daniel Sur ◽  
Calin Cainap ◽  
Simona Visan ◽  
Daniel Cruceriu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Liver Metastasis ◽  
Liver Metastases ◽  
Cancer Progression ◽  
Dependent Manner ◽  
Mesenchymal Transition ◽  
Cancer Management ◽  
Incidence And Mortality ◽  
The Impact

Colorectal cancer (CRC) is one of the most commonly diagnosed malignancies with a high incidence and mortality rate. An essential challenge in colorectal cancer management is to identify new prognostic factors that could better estimate the evolution and treatment responses of this disease. Considering their role in cancer development, progression and metastasis, miRNAs have become an important class of molecules suitable for cancer biomarkers discovery. We performed a systematic search of studies investigating the role of miRNAs in colorectal progression and liver metastasis published until October 2018. In this review, we present up-to-date information regarding the specific microRNAs involved in CRC development, considering their roles in alteration of Wnt/βcatenin, EGFR, TGFβ and TP53 signaling pathways. We also emphasize the role of miRNAs in controlling the epithelial–mesenchymal transition of CRC cells, a process responsible for liver metastasis in a circulating tumor cell-dependent manner. Furthermore, we discuss the role of miRNAs transported by CRC-derived exosomes in mediating liver metastases, by preparing the secondary pre-metastatic niche and in inducing liver carcinogenesis in a Dicer-dependent manner.

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